Onslaught of Champions

Further development for this modpack has halted. A new one is in the works that'll have the same/similar features as the 1.12.2 modpack.

Features:
Start with 3 hearts and work your way up to 2 rows of hearts.
Vanilla and modded bosses are more powerful.
Mobs in other dimensions are more tougher than in the overworld.
Tinker's Construct and Construct Armory. (Definitely needed in order to take on the toughest foes.)
Lengthy progression in terms of gathering for the best equipment.
And much more that I cannot think of.

Suggestions are appreciated if you even bother playing this.