[Now that he's not throwing what was essentially a temper tantrum with knives involved, Ivar can at least give fair warning as to why he was upset and worried about his father getting involved with Dodger.]

I've known him longer than you and I can tell you he's like a fire. He burns up whoever he touches. He cares for no one but himself and is set on a path of self-destruction. His goal seems to be to take as many people with him before I finally get around to killing him.

[This last part is simply stated as a goal like anything else Ivar has set out to achieve. He looks down. The hand on his glass tightens and it visibly creaks under his strength.]

I hated him initially because he's like everyone else who's ever looked at me and saw nothing. Just though I was someone weak and useless. I made him hurt badly enough to be scared of me. Now it's because he seems set on finding ways to hurt me. Not physically, you understand, because I always come out on top whenever we fight. He wants me to hurt emotionally.

[He finally looks back up to Ragnar and there's a vulnerable look on his face, something almost no one would ever see but the few people Ivar counted among his family.]

That's why I was worried about you. I know you well enough to know you'll keep going down the road of your own self-destruction well enough without any help from him.