Sir Oathkeeper

Vigilance, Ward 2
{t}: Target creature gains Hexproof until end of turn.

{1}: Search deck for Treasure Trove Guardian and place in hand, shuffle the library afterwards.
{3}: Create 3/3 Guardian Artifact Creature with Defender.

When Sir Oathkeeper is dealt damage, you may return an artifact you control to your hand. If you do, prevent that damage.