Sam
Okay, brief and yet full version of what happened?
Jeremy (with Elena) did not kill Kol to protect Jeremy. Jeremy is something called a Hunter. (Not like you are, but closer to Buffy's style, mystical calling and all that) The more vampires he killed, the greater a Mark on his body grew. That Mark was a map to a cure for vampirism. Kol traveled with some witches back in the day, and he knew things about the cure and what finding it would unleash (a dude called Silas, first immortal, total douchebag) and he was actually shit scared about it. So he wanted to stop Jeremy and compelled Damon to kill him. Because if a vampire kills a Hunter, there's this seriously horrible curse that happens, meant to drive said vampire insane.
So this is where the "protecting Jeremy" part of the bullshit comes into it. But. There was a way to break the compulsion on Damon. Something I was going to help with, using the dagger on Kol to immobilize him. That would have released Damon, protected Jeremy and not killed anyone.
But that wasn't good enough for Elena. When an Original dies, every vampire on their bloodline dies with them. So she worked it out, kill Kol using the White Oak stake, and it meant in one go Jeremy would massacre tens of thousands of vampires and complete the Mark, leading Elena to the cure she wanted. That was why she did it. Tens of thousands of vampires, just like Lexi or Lee or Rosemarie or the Salvatores, suddenly dying with no idea why. There was also a second part of the plan, that if killing Kol didn't kill quite enough vampires to complete the Mark, they were going to kill me too, eliminate my bloodline too.
They murdered my brother for their own gain. There was no protection, we had another plan to deal with that. So knowing that, can you really blame Kol for reacting when she turned up? For saying if she came near him, he would kill her? How would you feel, if someone who murdered Dean danced into town and acted like the victim? She has fully admitted that she would do it all again if she could go back. She's killed more people than my entire family combined, two of my brothers. So yes, I hate her, but I think I'm allowed, don't you?
If she stays away from us, she won't be harmed.
I don't know why your wife has such hatred for me, by the way. I've never done anything to her. When you were gone, she went ballistic and I get why. She threatened to torture me to prove it could be done, and I told her if it would make her feel better then go for it. I have never asked for an apology for that threat, nor do I expect one, because I know why she was going so crazy. She had lost you, she had no idea if she would ever get you back. I know what grief like that can do, and better she take that rage out on someone who can survive it like me than someone who would die. That's why I invited her to my wedding. But I am honestly afraid all over again that she's going to attack me or curse me, just to prove it can be done.