I'm actually just about to face Wrexsoul in my game. xD I'm trying to collect the espers, so yeah. I was told a 'strategy' of "use this spell, you'll win immediately" or something. Which doesn't sound much better than "go all out attack when he's doing this thing". To be fair, though, I must concede that I was considering only end-bosses when I was making my decision. If you include every damned boss out there then obviously even easy mini-bosses can involve some kind of strategy (eg. Scorpion Robot Thing on FFVII). It's the end-bosses which I've always either walked, or found that what was wrong with my strategy was merely "you're not a high enough level yet". Which for me didn't really mean strategy, it meant power. If we're going to ask which end-boss had the best gameplay, I'd struggle to make a decision... so many choices!