Umkas, the Exploder

Whenever you cast an Artifact, Create a 0/2 Artifact Turret Token with "{t} Deal 2 damage to target creature".

Umkas gains Ward {x} where X is half the number of Turrets you control rounded up.

{t}, Sacrifice a Turret: Give target artifact you control Indestructible until the end of the turn.
{t}{x}, Sacrifice a Turret: Return target artifact with mana value X from your graveyard onto the battlefield under your control.