Untap, Upkeep, Attack with both. Block?
Spidey: 16
Hand: 8
In Play:
(T) Island
(T) Swamp
(T,T) Forest x2
(T,T,U) Mt x3
Seal of Doom (Sac ~: Destroy target nonblack creature. It can't be regened)
(U) Trickster Mage (1/1, U, T, discard a card: I may tap or untap target artifact, creature, or...