Aizaki, Reflection Sanctuary

Eiyawa enters the battlefield tapped.
{t}: Add {w}
Serenity (Whenever you cast an instant or sorcery,
put a Serenity counter on it.)
{t}, Counter a spell you control with a Serenity
counter on it: Put a +1/+1 counter on target
creature for each Serenity counters on the
countered spell.