Champion mastery should allow people to choose the title they use once they have them all unlocked
I'm just saying, Reaper sounds cooler than Slayer. The angel of death is referred to as the Grim Reaper for a reason. It's not like it'd be a significant change, but it'd be a nice preference change.
Like, imagine if Spirit Guard Udyr only gave one icon. Like, what if it just gave bear stance icon because Riot considered it the most "iconic." But some people would rather a different stance, it's solely preference.