Braekun, Valeri's Challenger

Whenever Braekun, Valeri's Challenger is dealt combat damage to by another creature, you may have Braekun fight that creature.
Whenever Braekun, Valeri's Challenger fights, it gets +0/+2 until end of turn.
"I fought a valkyrie once. It was fun. She struck me down in two hits then flew away because I was weak. I was crawling for two days before Valeri nursed me back to health. Then I crawled for one more."