ArcaneTweaks
T.O Magic 'n Extras - Iron's Spells Addon
Adds high-quality & immersive spells, boss, weapons, equipment, and MORE! Integrated with L_Ender's Cataclysm, Alex's Caves etc.
Doomlike Dungeons
Causes procedurally generated dungeons rembling Doom levels to be placed in worlds
BetterEnd Forge
An unofficially maintained continuation of BetterEnd for Forge 1.20.1, bringing the latest BetterEnd content to Forge alongside bug fixes, compatibility improvements, and expanded End world generation
Goety - The Dark Arts
Perform necromancy and dark rituals using the power of souls. Highly configurable.
Reskillable Reimagined
RPG Leveling Mod, 8 default skills with up to 8 custom skills configurable!
Majrusz's Progressive Difficulty
Mod that progressively increases the game difficulty over time.