The Crystal of Truth

When The Crystal of Truth enters the battlefield,
transform all pairs of Mystics and Skeksis you
control into their UrSkek forms. Remove all
darkening counters from all permanents.
{2}{w}{w}, {t}: Until end of turn Gelflings you
control gain "When this creature dies, return
it to its owner's hand."
{1}{w}, {t}: Put a +1/+1 counter on all tapped
creatures you control and two Loyalty counters
on each planeswalker you control