Ivar was testing him to see how he would fare under actual battle conditions. After all, opponents didn't politely stand back and wait for you to be ready to go. It was kill or be killed out there, so he was going to make sure the people in this city were prepared for battle.

There's a smirk on his face when Kirk taunts him. Challenge accepted then. With one hand, he moves his wheelchair forward. Then he lets loose with a crushing blow that Jim will be able to feel all the way up the arm holding the shield, roaring the entire time in that way that everyone tends to assume Vikings sounded like in battle. It was a good psychological tactic to psyche out opponents.

"Keep that spear up and use the length to your advantage," he says, calling out advice. "It's a nice long weapon, so try to keep your opponent at arm's length or longer."