Greg Universe, Steven's Dad

Soulbond (You may pair this creature with another unpaired creature when enters the battlefield.
They remain paired for as long as you control both of
them.)
At the beginning of your upkeep, put a Guitar
counter on Greg Universe, Steven's Dad.
As long as Greg Universe, Steven's Dad is paired
with a Gem creature, each of those creatures gets
+1/+1 for each Guitar counter on Greg Universe, Steven's Dad.