Yeah, you're right about the title. Sorry about that. I was worn out and tired last night when I came up with the thread. Cant' seem to change it now though.
Anyways, Jacen hasn't really gone around killing a crap load of people in each book, but he's gotten definitely darker and turning into his grandfather.
Spoiler (Highlight to read):
Not only did he kill Mara, he's kidnapped his daughter and tortured Ben. He pulled a DV and snapped one of his officer's neck in full view of his star destroyer staff, and tossed her across the bridge. Definitely living up to his Darth Caedus name.
Like you said, I hope that what was in your spoiler tags happens, if its going to happen, she's got a hell of a teacher.