I tried to balance all of AOW4 spells (if it seems impossible) but here it is.
Dragon Dawn DLC edition! (and free Wyvern update)

List of changes (if not listed , rest of the effects are unchanged in that spell)

Order
Tome of Zeal  > Condemnation does 20 Damage
> Fanatical workforce now gives 40 production
Tome of God Emperor > Wrath of Emperor condemned lasts 3 turns

Materium
Tome of Enchantment > Spell-Tempered Shields gives 2 resistance
Tome of Winds > Windborne Scouts now gives very fast movement too

Chaos
Tome of Horde > Blaze of the Horde (nerfed) now gives 1 damage per Non tier1 unit (and same 3 dmg per tier1 unit)
  > Houndmaster unit was nerfed too much in dlc (-30 and -25hp). We replace that with -20 hp to both houndmaster and warhound.
Tome of Pyromancy > Immolate reduced cost to 15 mana and 15 casting points.
Tome of Mayhem > Sow Confusion now gives 2x Misfortune
Tome of Pandemonium > Mass Hysteria now has 2 hex radius            
         > Havoc Magic now has 60% chance
Tome of Devastation > Focus of Devastation now has 90% chance
Tome of Demon Gate > Abyssal Flames does 20 Damage
             > Sacrificial Slaughter does 20 Damage
Tome of Chaos Channeling > Demonic Focus now Heals 10 HP

Astral
Tome of Amplification > Chain Lightning now arcs 1 more time (4 targets total)
Tome of Warding > Static Shield now lasts 3 turns
Tome of Summoning > Arcane Restoration now Heals 30 HP
    > Arcane bond does 40 damage on failed mind control, cost increased to 100 mana and 50 casting points
Tome of Teleportation > Emergency Teleportation now has 5 range
               > Phase - Ability now has 5 range
Tome of Astral Convergence > Arcane Maelstrom does 15 damage
                 > Cascading Power now does 7 damage per spell stack but has 20 mana upkeep, and infinite duration
Tome of the Arch Mage > Disruption Wave reduced cost to 200 mana and 80 casting points
 
Nature
Tome of Roots > Vine Prison now summons 3 Vines on 1 hex radius that last 3 turns (DLC nerf was too big)
Tome of Cycles > Parting Gifts now heals 30 HP in 1 hex radius on unit death
Tome of Nature's Wrath > Devolve (nerfed) now has 70% chance
Tome of Goddess Nature > Force of Nature now gives 30% crit chance and +6 blight dmg

Shadow
Tome of Cryomancy > Ice Coffin (nerfed) now has 60% chance to freeze
Tome of Necromancer > Rotting Explosion (nerfed) now has 1 hex radius but does 20/20 damage
Tome of Oblivion > Sleep of Oblivion (nerfed) now lasts 1 turn

mod version 3.1: (from Watcher update open beta changes) Some tooltips are NOT changed because devs will do it soon in game anyway..
Tome of Cryomancy > BLIZZARD now does 20 damage, now applies -3 Status Vulnerability instead of 2. Cost increased to 80 mana and casting points
Tome of Evocation > LIGHTNING TORRENT now does 20 damage, Now applies -3 Lightning Weakness instead of 2. Cost increased to 80 mana and casting points
Tome of Artificer: Artisan Blades: No longer applies to Ranged Units.
Tome of Zeal: Legion of Zeal now affects Ranged Units
Tome of Faith: Army Heal now heals 25 Hit Points instead of 20. cost increased to 80 mana/CP.
Tome of Oblivion: Fog of Insanity chance to inflict Insanity increased to 20%
Tome of Amplification > Amplified Arrows: Damage Reduced to +2 Lighting and decreased the Physical damage penalty to -1.
Tome of Pyromancy: Fiery Arrows: Damage Reduced to +2 Fire and decreased the Physical damage penalty to -1.
Tome of Roots: Poison Arrows: Damage Reduced to +2 Blight and decreased the Physical damage penalty to -1.
Tome of Cryomancy: Frost Arrows and Frost blades: Damage Reduced to +2 Frost and decreased the Physical damage penalty to -1.
Tome of Terramancy: Earth Shatter damage increased to 20 from 10. cost increased to 100 mana/CP.
Tome of Crucible: Meteor Arrows extra damage reduced to 4.
Pyroclastic Eruption damage increased to 20 from 15. cost decreased to 100 mana/CP.
Tome of Cycles: Projectiles of Decay: Reduce the chance of applying Decaying from 90% to 60%
Tome of Nature’s Wrath: Destructive Regrowth damage increased to 20 from 10. cost decreased to 100 mana/CP.
Tome of Inquisition: Burden of Guilt damage increased to 20 from 10. cost increased to 80 mana/CP.
Tome of Glades: Glade Runner - Ability now Applies 2 Marked and 1 Sundered Defense and resistance.


compatible with any mod that doesnt change these spells properties. should work on existing saves. have fun!

----------------------------- INSTALLATION

first, if you installed my previuos mod for vanilla, DELETE folder:
Documents\Paradox Interactive\Age of Wonders 4\Mods\spells

then as usual unzip files to your "\Documents\Paradox Interactive\Age of Wonders 4\Mods" folder (create one if u dont have)

enable mods in your AOW4 launcher (dowser.exe in game folder)
> playset
> add new playset (needs to be done only once - first time)
> add mod to playset, check if "spells" mod is green (enabled) and play.
if you have more mods, just add "spells" to your existing playset.