Sharla, Medic Sniper

When Sharla, Medic Sniper enters the battlefield, put three Rifle counters on it.
Remove a Rifle counter: Prevent all damage that would be dealt to target creature this turn.
Remove three Rifle counters: Target creature gains Indestructible until end of turn.
At the beginning of your upkeep, if Sharla has no Rifle counters on it, you may pay {3} and place three Rifle counters on it. If you don't, tap it.