Petty Thief

Level Up {b} (Put a level up counter on this activate
only as a sorcery)

LV 0-2 (1/2 with Skulk) Whenever you deal
combat damage to a player add {b}.
LV 3-6 (1/3 with Skulk) At the beginning of
your upkeep take control of target token artifact.
LV 7+ (1/5 with Skulk) The first 3 treasure
tokens you sacrifice each turn sacrifice for an additional {b}.