The first one was Surtur, obvi. I did everything I could to prevent it and Asgard still hated me. So when I found Leah, we decided we had had enough. Why not let it all burn?

Together we tricked Surtur, but a good amount of damage had already been done. Hela aimed to finish the job. This time Leah and I retrieved the fear crown from Nightmare and others, and with its power, we managed to overthrow Hela. With Leah on the throne, she ceased to exist.

Then there was Heven, once it was reunited with the World Tree. Leah and I convinced them there was point in fighting, with their enemy already defeated. Thus there was peace in Asgard for all time.