Aged Scholar

Level Up {u}(Put a level up counter on this, activate
only as a Sorcery).
LV 0-3 (1/2 with Prowess) Whenever you cast an Instant or Sorcery that doesn't target an
opponent or their creatures create a clue token.
LV 4-7 (2/3 with Prowess and Skulk) Once per
turn sacrificing a clue token counts as casting an Instant or Sorcery.
LV 7+ (3/4 with Prowess, Hexproof and Skulk)
At the beginning of your upkeep copy target
artifact, sacrifice it at the end of your turn).