I guess this will be my submission:

Spoiler: Text
Chzoen Trawler 3UU
Creature - Elemental Rogue
Flying, Timeshift (This creature deals damage to players in the form of 15 seconds of clock time.)
{1}, Discard a card, pay 1 minute: Draw a card.

The Chzo are a race of sentient balls of gas that live on time. A Chzoen trawler drifts through the mists above the continent of Zomine, collecting treasures that gravity forgot, and offering them as trade. They don't ask for much. A few minutes will be enough...

I consider my set pitch 4/5ths done. I've been speaking with friends about possible replacements for Desperation. The mechanic names are mostly bad (I do like Transient) but that's fine for a pitch.