I'm curious to hear what folks think of the boss design in the ever-contentious Mega Man Zero series.
I love the Zero bosses. I'd argue that they're, generally speaking, the best Mega Man bosses ever. In particular, the 4 Guardians in Zero1(in Zero2, they changed for the worse, and Phantom was gone). I like how they flinch when hit, like you. It makes it feel more like a real fight, and less like you-versus-giant-thing.
I personally liked some of the attacks bosses would get if you had an S-rank-
This was awesome too. My favorite was Phantom's. He'd start teleporting to random points on the screen, pausing between teleports to throw kunai at you. He'd continue for a long while, unless you forced him to end it by hitting him 3 times; the catch is, he was invisible the whole time. So basically, each time he threw a pair of kunai, you had just over 1 second to get over there and hit him before he teleported again.
Here's one: Yunalesca, from FFX. Her first form would counterattack everything; physical attacks with blindness, spells with silence, you know. But that was just to soften you up for the real boss. Her second form only has 3 attacks: Hellbiter, Regen, and Cura. Hellbiter inflicts Zombie on your party, and the other two are healing spells. Since healing spells actually
hurt Zombies, you can do the math there. So obviously, you want to cure Zombie as soon as possible. But when you defeat her second form, she casts Megadeath, which instantly kills your entire party...except for Zombies. Her third form continues to use Hellbiter, and on your Zombies, the more powerful Curaga, which can kill party members with lower HP in a single hit. And now she periodically uses Megadeath. The end result is that you have to maintain a balance of party members, both Zombie and non-Zombie, so that no one attack can kill everyone.