Mana bars should have one tick mark at 100 mana

I think it would be a nice clarity improvement to have a single tick mark (like health bar) on the mana bar. It would help give context to how out-of-mana a champion is. Specifically, it would highlight whether a champion has enough mana to ult.

The reason I propose only a single tick mark is because how large a champion's mana pool is largely meaningless during combat except when it's low. During an all-in or trade, it doesn't matter if the lux has 400 or 600 mana, but it does matter if she only has 150.