Usually In games, milestones are rewarded.
And I consider champion mastery levels as a milestone, So why there is no reward?
And before you say that the level itself is the reward, Stop for a moment and think how fucked up it is.
I'm currently holding on multiple level 6 upgrades, just because the only prize upgrading gives Is the ability to buy level 7 emote on this particular champion.
the emote is not even a prize!! You still have to pay BE to get it.
In my opinion it would be more encouraging to play new champions if the milestones are properly rewarded, Instead of being penalized by -3000 BE.
Maybe make the upgrade automatically and give the emote as a reward, or OE or BE, Honestly even discount on that champion skins will be a nice reward for certain players