The Vampire Diaries 2X21: The Sun Also Rises

This absolutely felt like it could have been the season finale. What the hell are we about to get into next episode?

It seems like Klaus has everything he needs, so the ritual begins. He's got Jules, Jenna, and Elena all trapped in rings of fire, ready to be killed as needed. Jules is first, it's a simple affair. Klaus doesn't really put much into it.

Jenna is next, however, Stefan shows up and asks Klaus to trade Jenna for himself. Klaus decides that Elena can chose who she'd like to die. She refuses, and Klaus says it fine, he's wasn't planning to entertain a trade anyway. He stabs Stefan in the back and lets him writhe there is pain while he goes after Jenna. Once released from the fire, she immediately goes for Greta (which I thought was a super smart play, kill the witch no more ritual), but she's unsuccessful, and Klaus kills her. Elena, as you might imagine, is distraught. And Stefan looks just as upset.

Klaus completes the ritual by drinking Elena dry. She's just lying there dead, while Stefan is lying there in pain unable to do anything (not that he isn't trying). With the ritual completed, Klaus begins to turn into a werewolf. This is when Bonnie shows up and nails him with all the witch power.

Damon pulls the stake out of Stefan, and grabs Elena, bringing her back to the witch house. Stefan stays to make sure Klaus actually dies. However, he doesn't. Right as Elijah is about to rip his heart out, Klaus claims he knows where the bodies of their families are and if Elijah kills him, he'll never find out. Elijah apologizes to Stefan and the two of them fucking fly away. The fuck. I don't know why I'm so surprised that Elijah didn't hold up his end up the bargain. I got lulled into a false sense of security.

Meanwhile, while all this is going on, Bonnie puts a spell on John to (I think) somehow trade his life for Elena's. So, when Elena does finally wake up, she's human and John is dead. So both Jenna and John are dead (I mean, good riddance for John, right) and Klaus is still alive? WTF. How did we get here? I mean, I so did not expect Jenna do die. Maybe Matt. Or Tyler. But not Jenna.

Oh, and let's not forget that Damon is still dealing with the werewolf bite. Stefan assures him that they will find a way to cure him, but Damon doesn't seem that optimistic. (Not that I blame him).

Question: So, Klaus is now a full vampire/werewolf hybrid; can he only change on a full moon? Or can he change at will? I cannot remember if they talks about this.