Fighting the chimera solo is annoying. On the last HP bar, you have to manage your stamina like crazy. Aside from perfect blocking (which is weird because you can't do it right when you get attacked; it seems like you have to do it slightly before), I
think you can riposte with Hindsight Slash if you dodge a paw swing during the backstep. I'm not sure if that's what happened or if I did enough damage to just knock him down normally. Maybe hitting the legs repeatedly will also topple him? I don't think you can regular guard against his swipes, either. It has to be the just defend guard, otherwise you should be getting out of the way instead of trying to block.
Anyway, playing it this way lets you see each attack pattern much more clearly:
The snake can physically attack you if you're within its range. It can also barf a field of poison that does constant damage to you.
The goat can cast a lightning spell, an ice spell, and a firebolt spell that all track you but can be dodged by moving out of the way. There is also a proximity AoE sleep spell that can get you.
The lion just kind of runs around and swipes you. He can pounce and also go into berserk mode after his roar. If you're close, he'll jump right over you during his pounce (the one where he rears up immediately before). If you're behind him, he'll donkey kick you. Interestingly enough, I don't think he bites. *Nevermind. He chomps on you if you're on the ground.
edit: The berserk pouncing crap is giving me Barioth flashbacks from MH Tri.
edit 2: I think he goes into berserk if he's the only part left alive. Leaving the goat alive and killing the lion after the snake seems much safer. Wow.