Keras Selyrian

Double Strike
This creature enters the battlefield with X rune
counters on it. This creature's power is equal to
the number of rune counters on it times 4. If
this creature has 3 or less rune counters on it,
this creature has reach. During your upkeep,
remove all rune counters from this creature and
pay {x}, then put X rune counters on this
creature. X cannot be greater than 7.