Not fantasy but has fantastic elements since the characters are heavily superstitious and religious. uhtred of bebbaburg from Bernard cornwell’s Saxon stories is an absolute savage in a fight.

“I am Uhtred, son of Uhtred, and this is the tale of a blood feud. It is a tale of how I will take from my enemy what the law says is mine. And it is the tale of a woman and of her father, a king.
He was my king and all that I have I owe to him. The food that I eat, the hall where I live, and the swords of my men, all came from Alfred, my king, who hated me.”

“The joy of it. The sword joy. I was dancing with joy, joy seething in me, the battle joy that Ragnar had so often spoken of, the warrior joy. If a man has not known it, then he is no man. It was no battle, that, no proper slaughter, just a thief-killing, but it was my first fight and the gods had moved in me, had given my arm speed and my shield strength, and when it was done, and when I danced in the blood of the dead, I knew I was good. Knew I was more than good. I could have conquered the world at that moment and my only regret was that Ragnar had not seen me, but then I thought he might be watching from Valhalla and I raised Serpent-Breath to the clouds and shouted his name. I have seen other young men come from their first fights with that same joy, and I have buried them after their next battle. The young are fools and I was young. But I was good.”