He was killed after a raid, hit by a javelin in the side, it is assumed it was thrown by a frustrated citizen after the retreat of the Iberian horsemen. This raid was right before Katrina, his wife, was to have a child. His last words were extracting a promise from Thorn to watch over his wife and son.
Weapons - Mikkel was noted to be one of Skandia's best warriors, said to be tall and lean, but hard muscled and contains the reflexes of a cat. His skill with a sword has been passed down to his son Hal. He is also fairly competent with an battleax, but is not as skilled as Thorn or maybe Erak.
Wrestling - It is assumed he is good at wrestling, as he competed to become Maktig, and it is noted by Thorn in the Invaders wrestling was a part of the competition. He was also noted to be the toughest opponent Thorn had faced, and it did not just say in Weaponry.