I like the idea of sets, but this is just tooo OP
"2 set: Ruin III no longer costs MP when casting against a target under the effects of Bio, Bio II, and Miasma." - maybe adjust that to..
"2 set: Ruin III no longer costs MP when casting while under the effect of Dreadwyrm Trance." - as the MP is already reduced, this wouldn't be as game changing.