Hello. 

The GD Defiler doesn't work with my version of Titan Quest AE Ragnarok to the extent of removing Masteries. 
After searching in various forums and racking my brains on how to get skills without taking the Mastery they belong to, I found an old save file from the Gold Edition of the game (back when the old Defiler still worked and I could edit characters to my heart's content). 

To install download the archive extract it and copy the "_Sara - COPY" folder into the save game folder (should be under: C drive > Users > your username > Documents > My Games > Titan Quest - Immortal Throne > SaveData > Main). 
Honestly, I'm not sure if you need all those files but better safe than sorry. The total size is a few MB. 

The character in her current state is way overpowered but has a lot of skills from different masteries. 
If you want to weaken the character use the Defiler to change the Health, Mana and Attributes values (currently it can do that much). 

Character skills (mostly maxed): 

Warfare: 
- Weapon Training 
- Dodge Attack 
- Dual Weapon Training 
- Jumpslash 
- Crosscut 
- Tumult 
- Onslaught 
- Ignore Pain 
- Hamstring 
- Ardor 
- Battle Rage 
- Crushing Blow 
- Counterattack 

 Defense: 
- Armor Handling 
- Adrenaline 
- Resilienece 
- Defensive Reaction 
- Rally 
- Inspiration 
- Defiance 
- Colossus Form 
- Sheildsmash
- Disable 
- Pulverize 
- Battle Awareness 
- Focus 
- Iron Will 
- Concssive Blow 

Earth: 
- Volatility  
- Core Dweller 
- Inner Fire 
- Wild Fire 
- Metamorphis 
- Fire Enchantment 
- Brimstone 
- Stone Skin 
- Ring of Flame 
- Soften Metal 

Storm: 
- Stormnimbus 
- Heart of Frost 
- Static Charge 
- Wisp Summoning 
- Eye of the Storm 

Stealth: 
- Envenom Weapon 
- Neurotoxin 
- Toxindislation 
- Delirium 
- Calculated Strike 
- Lucky Hit 
- Open Wound 
- Anatomy 
- Disarm Traps 

Hunting: 
- Woodlore 
- Art of the Hunt 
- Find Cover 
- Trailblazing 
- Herbalism 
- Marksmanship 
- Puncture Shot Arrow 
- Scatter Shot Arrow 
- Gouge 
- Volley 
- Takedown 
- Eviscerate 

Nature (currently selected as the first mastery): 
- Regrowth 
- Accelerated Growth 
- Dissemination 
- Heart of Oak 
- Tranquility 
- Permanence 
- Wolf Summons 
- Maul 
- Survival Instinct 
- Strength of the Pack 
- Sylvanny Nymph Summons 
- Overgrowth 
- Nature's Wrath 
- Renewal 

Spirit: 
- Deathward 
- Death Chillaura 
- Ravages of Time 
- Necrosis 
- Circle of Power 
- Lifedrain 
- Cascade 
- Outsider Summons 
- Temion 
- Arcane Lore 
- Enslave Spirit 
- Wraith Lords Summons 
- Death Nova 
- Wraith Shell 
- Arcane Blast 

Records (Dream): 
- Trance of Empathy 
- Psionic Touch 
- Psionic Bomb 
- Distortion Field 
- Nightmare 
- Hypnotic Gaze 
- Master Mind 
- Lucid Dream 
- Permonition 
- Temporal Flux 

I've taken the names from the GD Defiler, so some may be wrong (its skill section is cramped). 

Pros: 
+ The character only has one Mastery so Runes can be added. 
+ Allows insight into all of the old masteries without having to create multiple characters. 
+ Allows experimentation with a lot of different skills. 
+ Allows comparison of lots of different skills at maxed values (if you want to do calculation). 

Cons: 
- Is way overpowered without further editing. 
- Has a dumb name "Sara - copy" (originally it was a backup). 
- Is female (in case you want a male character). 

To use the skills, right click on a quickbar slot and assign a skill to it (It'll take a lot of remapping to test all the skills). 

Credits: 
Game creators: Iron Lore Entertainment, THQ and THQ Nordic.  
SoulSeekkor for making the TQ Defiler and GD Defiler.