I really want to make a game sort of like a twisted combination of FFXIV and DeltaRune/UnderTale.
Pretty much just select an attack, then deal with what attack the boss is dealing at you, but focusing on non-standard tells and snapshot damage.
Take a look at this fight. This is one of my favorites.
https://www.youtube.com/watch?v=pNUUiylMgFo