Sheoldred's Terror [Unknown Event] WTR045-S return it to the battlefield

return it to the battlefield under its owner's control with a flying counter on it

the price on your head is high

where X is the total power of creatures you control

Threshold — Nim Mongoose gets +1/+0 for each artifact you control as long as seven or more cards are in your graveyard

Sheoldred's Terror [Unknown Event] WTR045-S return it to the battlefieldSet: Unknown Event Type: Instant Rarity: Common Cost: {B} Destroy target creature not originally printed in an Argentum expansion. (Mirrodin, Darksteel, Fifth Dawn, Scars of Mirrodin, Mirrodin Besieged, New Phyrexia, and Phyrexia: All Will be One are Argentum expansions. Argentum is Karn's original name for that plane, now you know!)