I think the deaths were well executed, personally. And the fact that Korra herself ended up in a wheelchair with such a sick and weak semblance is more than enough buildup to the next season, if you ask me. It begs a really big question of what now, that the Avatar is basically out of the picture? Do any of you remember what happened last time the Avatar was gone? Oh, right, The Hundred Years War, air nation all but annihilated and hey, four whole seasons of The Last Airbender in order to sort of kind of get things on track again.
Tenzin understands what it means to have Korra incapacitated, the president knows, Lin knows. Even Varrik probably would catch on to the potential dangers for wholly illogical reasons. What happened was a really big opening and a really big question mark for season four: Anything can happen now.
Back on the deaths though; P'Li got overly comfortable with her special bending, it made her open to Suyin's attack. Contrast and compare how Lin and Su were fighting, mixing earth and metal forms both to attack and defend. P'Li apparently forgot that she was a fire bender and started relying on standing in place and blowing things up. She wasn't playing around, sure. She would have killed Lin if it wasn't for the impromptu helm, yes. But it only really happened because she never thought to be less flashy and consider she was outnumbered. And it is also a testament to Suyin's skill, landing that particular move was not something just anyone would be able to do.
Ming-Hua's case points to something about Mako that no one considers... He never once killed anyone, nor did he fight to murder people. The instance of his lightning bending was in a power plant, as a job, to charge batteries. He was a friggin' detective, not a raider. And lightning is dangerous and unforgiving. Not something he would ever use against another human; it's just not on his personality to do it, he's not going to kill someone out of his own free will unless he absolutely has not a single other choice left. The fact that he was driven far enough to pull it off shows, again, just how damn strong Ming-Hua was.
And Ghazan choose to go out on his own terms, fitting for a moving volcano. Look at all other times he fought and he's always been the most cheerful of the bunch, and one of the most tame. Despite wielding what's possibly the most gratuitously destructive form of bending shown so far, he never did more collateral damage than what was strictly necessary to get his point across. Hell, he was hesitant to melt the Northern Air Temple too, and even doing it, he didn't directly harm the four inside; left them for dead, sure. Directly kill them? Nope. Come him being cornered, he simply made his choice. Similar to how Mako ultimately decided to thunder away, he choose to let go of restraint and just blow everything up. Very fitting to his character, on my view.
On Zaheer, however... He finally went crazy. Which took a while, but it's the same as Amon and Asslock (no, I probably won't ever stop calling him that). They thought they had won, all of the hinges came off. Same as Zaheer. The fact that he's in prison now probably means he's gone for good; messages from a kid's show, after all. Morality 'n stuff. The rest of the Red Lotus? If they can learn anything from what happened, is that it doesn't matter too much how well off the avatar herself is, there are tons of people willing to protect her. And they're no slouches. The four strongest benders shown so far couldn't pull it off, a punk nobody who can carry a bowl of poison probably wouldn't get anywhere close.
Again, my question, and what I feel like the big opening for the fourth season is: What now?
As for my personal reading into it; Vaatu. Korra's avatar mode is a lot stronger and a whole level more ruthless than Aang's was. What's the difference between them? Aang was a pure light Avatar of Rava. Korra is a dual avatar with both Rava and Vaatu. And conflict strengthens Vaatu. Not to mention Korra is really really depressed which is likely to be nursing the dark side with great care. What, then, is to be done if the threat to balance turns out to be the avatar herself?
