Clera's Oath to Loyalty

As an additional cost to cast Clera's Oath to Loyalty remove a +1/+1 counter from a creature you control.
When Clera's Oath to Loyalty enters the battlefield you may search your library and/or graveyard for a card named Clera, Champion's Student and put it in your hand. If you searched your library this way, shuffle it.
Creatures you control get +1/+1 and have haste.