PathOfCorruption

Perfect Feature Injection for any Minecraft Modpack!

Adds 4 new weapons with special abilities, 3 new bosses, many new items, and more!
Adds another side of progression in the game. A direct path along the mod in which you fight no mobs get new weapons and get stronger.

I would say there's not enough features to play by itself, but put this in a modpack and it'll just make it that much better.