Isekai Mod
If you want to help out with development, please go to https://github.com/JohN100x1/IsekaiMod.

Requirements

• Unity Mod Manager.
• TabletopTweaks-Core.
  

Installation

• Open Unity Mod Manager and go to the 'Mods' tab.
• Drag and Drop the TabletopTweaks-Core.zip file into Unity Mod Manager.
  

• Drag and Drop the IsekaiMod.zip file into Unity Mod Manager.
  

New Content
New Classes & Archetypes

• Isekai Protagonist
  

        - Spontaneous caster that uses Charisma.
        - Has a really powerful spellbook that has spells from all other classes.
        - Has extra feats like the fighter but not limited to combat feats.
        - Starts of with the `Plot Armor` feature which make them hard to kill.
        - Has overpowered abilities.
- Can merge their spellbook with angel or lich.
- Can choose a familiar or animal companion... or a deathsnatcher.
        - Can choose a legacy class feature (features from other classes).

• God Emperor (Isekai Protagonist Archetype)
  

        - Spontaneous caster that uses Wisdom.
        - Has powerful scaling immunities and auras.

• Edge Lord (Isekai Protagonist Archetype)
  

        - Has alot of extra attacks.
        - Uses dexterity for damage and attack rolls.

• Hero (Isekai Protagonist Archetype)
  

        - Focuses to protective auras for allies.
- Uses charisma for damage and attack rolls.

• Mastermind (Isekai Protagonist Archetype)
  - Intelligence based caster that memorizes spells like an arcanist.

        - Spellbook has 10th level spells.

• Overlord (Isekai Protagonist Archetype)
  

- Has much more Overpowered Abilities.
New Features

• Exceptional feats: Strong feats that can be chosen in place of a feat/bonus feat.
  

        - Mythic feat: You can choose a mythic feat instead of a normal/bonus feat.
        - Effect Immunity: You become immune to a specific effect. (e.g. poison, bleed, charm etc.)
        - Mighty Summoning: Your summons get +5 HP, +1 attack, and +1 AC per character level.
        - Magical Summoning: Your summons get +5 HP, +1 spell penetration, +1 spell DC, +1 spell damage, and +1 to saving throws per character level.
        - Forbidden Summoning: Your summons get +10 HP, and +1 to all attributes per character level. (requires Mighty and Magical Summoning).
        - Ferocious Summoning: Your summons have 2 more attacks and +10 speed. They also get +1 sneak attack per level. (requires Forbidden Summoning).
- Exceptional Weapon: Your attacks get an additional enchantment. (e.g. Corrosive, Flaming, Frost, etc.)

• Plot Armor: Get bonus on AC and Saving throws based on character level.
  

• Special Power Feats: A selection of bonus feats which have very good effects
  

        - Alpha Strike: Automatically confirm crits.
        - Beta Strike: Get an extra attack with a -4 damage penalty.
        - Gamma Strike: Ignore concealment and your attacks count as adamantine.
- Omega Strike: Increase your damage multipler by 1.
- Sigma Strike: Increase your critical threat range by 2.
        - Mundane Aura: Get immunity to sneak attack and critical hits.
        - Training Montage: Get a +8 bonus to all attributes.
        - Body Strengthening: Get a DR/— equal to character level.
        - Spell Negation: Get Spell resistance equal to 10 + twice character level.
        - Extreme Speed: Allies within 40 feet of you get a speed bonus equal to 5 times your character level.
- Regeneration: Get regeneration 10/acid or fire (requires character level 10).
        - Channel Positive Energy: You can channel positive energy.
        - Channel Negative Energy: You can channel negative energy.
        - Kinetic Power: You can select a kinetic blast (air, earth, fire, water).
        - Sneaky Magic: You can add your sneak attack damage to spells against flat-footed.
        - Spell Master: Increase your spell DC by 4.
        - Magical Amplification: Your spell damage dice become d10.
        - Armor Saint: You can move at normal speed while wearing armor, reduce your armor check penalty to zero, and increase your max dexterity bonus.
        - Armor of Strength: Get a natural armor bonus to AC equal to Strength modifier.
        - Summon Beast: Summon a hydra, owlbear, roc, or minotaur.
        - Killing Intent: Enemies within 40 feet become shaken, frightened, and cowering.
- Reflect: Deal damage to enemies equal to damage you receive.
- Supermassive: Gain bonus HP based on your Constitution modifier. You also get fast healing but have a penalty to AC.
        - Excalibur: Your weapon gains the holy and radiant enchantments. Your attack range is massively increased.
        - Unreactable: Enemies you attack are treated as flat-footed (requires character level 15).
        - Haggler: Vendor prices are reduced.
        - Mythic Class Feature: see below

• Overpowered Ability: Powerful gamebreaking abilities.
  

- AutoBolster: Bolsters every spell you cast.
        - AutoEmpower: Empowers every spell you cast.
        - AutoExtend: Extends every spell you cast.
        - AutoMaximize: Maximizes every spell you cast.
        - AutoQuicken: Quickens every spell you cast.
        - AutoReach: Gives more range on every spell you cast.
- AutoSelective: Exclude selected targets on every spell you cast.
        - Instakill: Kills target creature (no HP limit).
        - Dupe Gold: Get infinite gold.
        - Perfect Roll: Roll 20 on every d20 roll.
        - Super Buff: Apply many powerful buffs on you and your allies.
- Infinite Inventory: Get infinite carry capacity.
- Unlimited Power: Restore all ability and spell slots at will.
- Mind Control: Make an enemy creature fight for you.
- Summon Calamity: Summon a Devastator, Baphomet, Deskari, Nocticula, Mephistopheles, or Areshkagal.
        - True Resurrection: Resurrect a dead companion (no diamond cost).
        - Supreme Being: All your attributes have a base value of 30.
- Meta Luck: Always take the higher of two d20 rolls.
- Power Leveling: Gain extra experience when you kill an enemy.
        - Master Summoner: Gain extra summons to the total number of creatures summoned.
- Overpowered Aura: 4 different alignment based auras which give either extra attack(s) and/or damage.
- Underpowered Ability: A selection of less powerful effects.
        - Mythic Class Feature: see below
        - Dual Legacy: Pick a second base class to get abilities from.
        -  The following requires TabletopTweaks-Base:
            - Auto Rime: Cold spells entangle the target for a number of rounds.
            - Auto Burning: Acid and fire spells cause acid or fire damage on the next round.
            - Auto Flaring: Light, fire, and electricity spells cause the dazzled condition.
            - Auto Piercing: Spells treat target's SR as 5 lower than actual SR.
            - Auto Solid Shadows: Shadow spells are 20% more real.
            - Auto Encouraging: Increase spells' morale bonus by 1.
            - Auto Intensified: Increase spells' max damage dice by 5.
            - Auto Elemental (Acid): Replace or split spells' damage with acid.
            - Auto Elemental (Cold): Replace or split spells' damage with cold.
            - Auto Elemental (Electricity): Replace or split spells' damage with electricity.
            - Auto Elemental (Fire): Replace or split spells' damage with fire.

• Mythic Class Feature: Access to a mythic class feature not your own
  

        - Angel Mythic Class Feature: possible selections include the angelic halo and sword of heaven and their buffs
        - Azata Mythic Class Feature: the superpowers
        - Lich Mythic Class Feature: the lich powers
        - Trickster Mythic Class Feature: the trickster skill specializations
        - Mythic Aeon Spells: Aeon Spells in Protagonist Spellbook
        - Mythic Angel Spells: as above but for Angel
        - Mythic Azata Spells: as above but for Azata
        - Mythic Demon Spells: as above but for Demon
        - Mythic Lich Spells: as above but for Lich
        - Mythic Trickster Spells: as above but for Trickster

• Legacy Class Feature: Pick a base class to get abilities from:
  

        - Barbarian Legacy - Ball of Rage
        - Bard Legacy - Musical Prodige
        - Dread Knight Legacy - Dread Lord (requires Expanded Content)
        - Paladin Legacy - Hero of Light
        - Kineticist Legacy - Kinetic Knight
        - Kineticist Legacy - Kinetic Lord
        - Kinetic Legacy - Soulbinder
        - Kinetic Legacy - Noble Soul
        - Magus Legacy - Spellblade
        - Oracle Legacy - Seeker of Truth: does not grant its selections retroactivly, so best picked early.
        - Rogue Legacy - Supernatural Thief
        - Shaman Legacy - Spirit Beacons
        - Sorcerer Legacy - Chimera: does not grant its selections retroactivly, so best picked early.
        - Fighter Legacy - Basic Fighter
        - Fighter Legacy - Two Handed Fighter
        - Fighter Legacy - Guardian Shield
        - Monk Legacy - Daoist Martial Artist
        - Monk Legacy - Fist of a Dragon
        - Skald Legacy - Metal Singer
        - Skald Legacy - Silver Tongue
        - Skald Legacy - The Voice
        - Druid Legacy - Nature Mage
        - Shifter Legacy - Ditto
        - Shifter Legacy - Stinger
        - Shifter Legacy - Shapeshifted Baby Dragon
        - Inquisitor Legacy - Domain Lord
        - Inquisitor Legacy - Judge
        - Inquisitor Legacy - Tactician
        - Witch Legacy - Pactmaker
        - Bloodrager Legacy - Chimeric Rager
        - Player Legacy - Computer Nerd
        - Player Legacy - Part Timer
New Animal Companions

• Deathsnatcher: A chaotic evil monstrous humanoid companion that can cast the animate dead spell. (Warning: very unbalanced)
  

New Mythic abilities

• Mythic Overpowered Ability: Gives you another overpowered ability.
• Mythic Special Power: Gives you another Special Power.
  

New Heritages

• Isekai Angel (Aasimar Heritage): A powerful heritage for Aasimar that gives you wings and a powerful holy damage ability.
  

• Isekai Succubus (Tiefling Heritage): A powerful heritage for Tiefling that gives you wings and a powerful charm ability.
• Isekai Vampire (Dhampir Heritage): A powerful heritage for Dhampir that has fast healing and many immunities.
• Isekai Dark Elf (Elf Heritage): A powerful heritage for Elf that gives you the Drow Poison ability.
• Isekai High Elf (Elf Heritage): A powerful heritage for Elf that increases the number of spells you can cast per day.
• Isekai Wood Elf (Elf Heritage): A powerful heritage for Elf that have extra speed.
• Isekai Spriggan (Gnome Heritage): A powerful heritage for Gnome that gives you a size alteration ability.
• Isekai Furry (Kitsune Heritage): A powerful heritage for Kitsune that has fast healing and extra speed.
  

New Backgrounds

• Tabletop RPG Player: Adds all Lore and Knowledge skills as class skills. Lore and Knowledge skills use CHA instead of WIS/INT.
  

• Martial Artist: Get proficiency in all exotic weapons.
  

• Salaryman: Adds perception as a class skill. Perception uses CHA instead of WIS.
  

• Highschool Student: Get a +1 trait bonus to all attributes.
• Otaku: Adds all skills as class skills except Persuasion.
• Reborn Demon Lord: Get a +2 trait bonus to Strength and Electricity resistance 20.
• Gamer: Get a +8 competence bonus to all knowledge, lore, and perception checks.
• Beta Tester: Get +4 Initiative and adds lore, knowledge and perceptions skills as class skills.
• Demonic Cultivator: Adds athletics and mobility as a class skills. Uses the higher of STR and DEX for athletics and mobility checks.
• Enlightened Sage: Adds lore, knowledge, and perception skills as class skills. Uses the higher of INT and WIS for these checks.
• Musician: Adds Persuasion as a class skill. Has a +2 bonus to caster level and DC for Sonic spells.
• Rationalist: Has Immunity to spell and spell-like abilities but cannot cast spells.
  

New Deities

• Truck-kun: A god of transportation.
• Aqua: A goddess of water.
• Ristarte: A goddess of healing.
• Administrator D: An ultimate god of evil.
  

New Dialogue

• Prologue, speaking with Hulrun at Kenabres Festival.
• Prologue, speaking with Horgus at Neathholm.
• Prologue, after finding Radiance in the Shield Maze.
• Act 1, first encounter with Minagho in Gray Garrison.
• Act 1, speaking with Anevia in the Bad Luck Tavern.
• Act 1, speaking with Irabeth in the Bad Luck Tavern. 
• Act 1, speaking with Finnean.
• Random encounter, during drow ambush.
  

Isekai Protagonist Spell progression
Spells per Day table
+--------+------+------+------+------+------+------+------+------+------+
| Level  | 1st  | 2nd  | 3rd  | 4th  | 5th  | 6th  | 7th  | 8th  | 9th  |
+========+======+======+======+======+======+======+======+======+======+
| 1      | 3    |      |      |      |      |      |      |      |      |
| 2      | 6    |      |      |      |      |      |      |      |      |
| 3      | 9    | 3    |      |      |      |      |      |      |      |
| 4      | 12   | 6    |      |      |      |      |      |      |      |
| 5      | 12   | 9    | 3    |      |      |      |      |      |      |
| 6      | 12   | 12   | 6    |      |      |      |      |      |      |
| 7      | 12   | 12   | 9    | 3    |      |      |      |      |      |
| 8      | 12   | 12   | 12   | 6    |      |      |      |      |      |
| 9      | 12   | 12   | 12   | 9    | 3    |      |      |      |      |
| 10     | 12   | 12   | 12   | 12   | 6    |      |      |      |      |
| 11     | 12   | 12   | 12   | 12   | 9    | 3    |      |      |      |
| 12     | 12   | 12   | 12   | 12   | 12   | 6    |      |      |      |
| 13     | 12   | 12   | 12   | 12   | 12   | 9    | 3    |      |      |
| 14     | 12   | 12   | 12   | 12   | 12   | 12   | 6    |      |      |
| 15     | 12   | 12   | 12   | 12   | 12   | 12   | 9    | 3    |      |
| 16     | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 6    |      |
| 17     | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 9    | 3    |
| 18     | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 6    |
| 19     | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 9    |
| 20     | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 12   | 12   |
+--------+------+------+------+------+------+------+------+------+------+

Spells Known table
+--------+------+------+------+------+------+------+------+------+------+
| Level  | 1st  | 2nd  | 3rd  | 4th  | 5th  | 6th  | 7th  | 8th  | 9th  |
+========+======+======+======+======+======+======+======+======+======+
| 1      | 6    |      |      |      |      |      |      |      |      |
| 2      | 12   |      |      |      |      |      |      |      |      |
| 3      | 18   | 6    |      |      |      |      |      |      |      |
| 4      | 24   | 12   |      |      |      |      |      |      |      |
| 5      | 24   | 18   | 6    |      |      |      |      |      |      |
| 6      | 30   | 24   | 6    |      |      |      |      |      |      |
| 7      | 30   | 24   | 12   | 6    |      |      |      |      |      |
| 8      | 30   | 30   | 18   | 6    |      |      |      |      |      |
| 9      | 30   | 30   | 18   | 12   | 6    |      |      |      |      |
| 10     | 30   | 30   | 24   | 18   | 6    |      |      |      |      |
| 11     | 30   | 30   | 24   | 18   | 12   | 6    |      |      |      |
| 12     | 30   | 30   | 24   | 24   | 18   | 6    |      |      |      |
| 13     | 30   | 30   | 24   | 24   | 18   | 12   | 6    |      |      |
| 14     | 30   | 30   | 24   | 24   | 24   | 18   | 6    |      |      |
| 15     | 30   | 30   | 24   | 24   | 24   | 18   | 12   | 6    |      |
| 16     | 30   | 30   | 24   | 24   | 24   | 24   | 18   | 6    |      |
| 17     | 30   | 30   | 24   | 24   | 24   | 24   | 18   | 12   | 6    |
| 18     | 30   | 30   | 24   | 24   | 24   | 24   | 24   | 18   | 6    |
| 19     | 30   | 30   | 24   | 24   | 24   | 24   | 24   | 24   | 12   |
| 20     | 30   | 30   | 24   | 24   | 24   | 24   | 24   | 24   | 20   |
+--------+------+------+------+------+------+------+------+------+------+

Mod Support
This mod has support for the following mods.


TabletopTweaks-Base (2.5.2)
If you have the `TabletopTweaks-Base` mod, the Isekai Protagonist will have all extra metamagics as OP ability options.

MysticalMayhem (0.1.5)
If you have the `MysticalMayhem` mod, the Isekai Protagonist will have the 9th level Meteor Swarm spell added to its spellbook.

ExpandedContent (0.5.2)
If you have the `ExpandedContent` mod, the `Isekai Protagonist` will have all the new spells add to its spellbook. You also get to choose drake companions.

SpellbookMerge (1.7.1)
If you have the `SpellbookMerge` mod, the Isekai Protagonist will be able to merge its spellbook with Aeon, Azata, Demon, and Trickster.

Any Mod adding spells to the base classes
As of version 4.0.0 there is an option to create the Isekai spell list by merging most of the non mythic ingame spell lists. That means that as long as the mod loads in before this one and adds the spell to at least one of those lists the Isekai Protagonist gets it too.
The list of spell lists we merge for this is fairly comprehensive, Cleric, Wizard, Druid, all the base game domains, all the different wizard specialisation lists, Witch, ...
As such almost no spell should need work on our part to add support for it, if you find one please let us know.

Credits
Thanks to kjk001 for contributing alot to this repository, improving the code to use TabletopTweaks-Core as well as adding lots of content.
Thanks komoechan and Necht for fixes to the localization.
Thanks to WittleWolfie for creating this modding guide that helped me get started:

• https://github.com/WittleWolfie/OwlcatModdingWiki/wiki