Scion of the Wendigo

Whenever a legendary creature enters the battlefield under your control, you may put a
-1/-1 counter on Scion of the Wendigo.
Remove all -1/-1 counters from Scion of the
Wendigo: Put that many +1/+1 counters on a
creature you control named S'ja Kull, the Bloodhunger.
"He is coming. Surrender now, and he may devour
you quickly."