Caroline
Elijah IS saying "When I marry Katherine" which does make me roll my eyes every time. What Nik seems unable to actually grasp is that by trying to 'prevent' madness, he's making it ten times worse. Elijah is as stubborn as he is, and the more Nik pushes and threatens and throws tantrums, the more Elijah will declare he loves the little bitch and wants to "make her a Mikaelson". Which, sorry, never happen. Even if they marry, even if she calls herself Katherine Mikaelson, she'll never truly be part of the family.
I'm just sick of him being a giant hypocrite. Why is he being happy with you so different to me being happy with Stefan?