Okay yeah wow that was intense. I usually wait to watch because my site has it in good quality but a day after, but everyone was talking about it and I didn't want to be spoiled so I just went ahead and watched it.
I'm glad I'm not the only one who thought Mako was being an absolute idiot jumping into there. The lightning bending really surprised me so it was cool. Did he kill Ming Hua? I know in real life getting shocked for that long would probably kill a person, but in the Avatar world physics aren't quite the same with a lot of this stuff.
I guess it would make sense if she died, as P'Li died and Ghazan killed himself (hey, I finally know all their names!). I think him killing himself was kinda dumb because I still think he could've escaped. Aside from that though, I think each villain's defeat was perfect, instead of just generic "now we are finally stronger than you" they actually were each defeated by the logical counter to their special powers. I was actually thinking Ghazan would die by accidentally falling into his own lava, but I guess a guy being burned to death and melting would be way too disturbing, even for this show (although I guess they didn't have to show it and could just imply it like with P'Li).
I know killing people in cold blood is not really done in Avatar but I'm surprised Zaheer was just thrown back in prison instead of executed. He definitely needs to come back in season 4 (maybe he'll finally be redeemed?) even if they just visit him in prison like with Ozai in the comics. The first two villains were killed and all of Zaheer's team was killed, so for him to be still alive he should have a role in season 4. I hope for season 4 they ditch making a new villain that they have to fight and just make solving these social/political problems the source of conflict.
Lastly, did anyone else think it was kind of weird for Zaheer to get all mad at the end? The first time they failed he just kinda accepted it and decided to leave, and now while he's allegedly left all worldly attachments he can still get upset about something.
EDIT: Oh yeah, Bolin being a lavabender instead of a metalbender was cool. I thought he was going to eventually metalbend but betraying our expectations yet again was nice. I thought lavabending was one of those special powers like combustion, you can't really learn it, you have to be born with it. But I guess if that's the case, he was born with it but just never knew it o_o