This might be one of my favorite modpacks of all time in terms of concept, to be honest. The world needs more packs that deliver vustom experience, and a world overtaken by thaumcraft taint is super interesting.

Blightfall suffers from a lack of texture optimization (lookin at you, 32×32 stone textures) and a slow endgame, but the experience it provides more than makes up for its flaws.