In The Legend of Dragoon,there's Lenus. Here's some background; She's a magic spamming boss,and very few of your party members have any decent magic defense. She's also very fast,which usually equates to several concecutive turns.
The worst part? Her speed is INVERSELY PROPORTIONAL to how much health she has. Meaning she gets faster the more you hurt her. I was on the recieving end of 12 concecutive turns of powerful magic. Furthermore...Most of her spells are mass effect spells,meaning that they hit the entire party. And that's just round one.
Round two,she gets better armour,better spells,and a better melee stat. And...A Sea Dragon ally. THE sea dragon. Thankfully,she loses the whole speed crap.
And players are usually around level 15 by this point. The game is 4 discs long. You fight her during the second disc.