Eternal Witness and Lion's Eye Diamond on the battlefield.
({2} magic symbol) ({B} magic symbol) available.
Steps
Cast Saw in Half by paying ({2} magic symbol) ({B} magic symbol) , targeting Eternal Witness.
Holding priority, activate Lion's Eye Diamond by sacrificing it and discarding your hand, adding ({B} magic symbol) ({B} magic symbol) ({B} magic symbol) .
Resolve Saw in Half, destroying Eternal Witness and creating two token copies of it with base power equal to half the destroyed creature's power and base toughness equal to half the destroyed creature's toughness, rounding up each time.
The Eternal Witness tokens enter the battlefield, returning Lion's Eye Diamond and Saw in Half from your graveyard to your hand.
Cast Lion's Eye Diamond by paying ({0} magic symbol) .