Artifact, UB (2)
Rare
{T}, Sacrifice five artifacts: Take an extra turn after this one.
"I pray that I am never considered useless or old."
—Sharuum the Hegemon
Illus. Franz Vohwinkel

5/1/2009: One of the five artifacts you sacrifice may be Time Sieve itself.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern