When Olaf kills Baron
Since Olaf is a reference to Thor in a way, I think Olaf should get a different buff or a different buff name if he lands the killing blow on Baron, or even a quest to kill Baron, to reference the battle between Thor and Jörmungandr during Ragnarök. It would be cool to have more of these mini-buffs and mini-quests in the game to add more concept/detail and make getting kills or objectives feel more rewarding or purposeful, rather than just taking them to win.