Atheon, Vault TimeLord

Indestructible, Vigilance.
Atheon Enters the battlefield with X +1/+1 Counters. Then if X was 5 or more, Atheon Deals 5 Damage to target creature. Then if X was 10 or more, Deal 10 Damage to any Target. Then if X was 15 or more, Destroy all other Permanents.