I'll UB to Negate the March of the Returned. I assume that doesn't change your turn since you're tapped out.
Untap, upkeep
Attack with Spy and Messenger for 6, I assume combat resolves since you're tapped out. I'll choose #1.
Angelic Wall
Vial of Poison
Done
Spidey: 18
Hand: 2
Battlefield:
(T) Plains
(U,U) Swamp x2
(T) Mt
(T,U,U) Island x3
(T) Forest
(U) Vial of Poison (1, Sac ~: Target creature gains deathtouch ueot)
(U) Gnawing Zombie (1/3; 1B, Sac a creature: Target player loses 1 life and I gain 1 life)
(T) Merfolk Spy (3/3 from ctr; Islandwalk; Whenever ~ deals combat dmg to a player, that player reveals a card at random from his hand) *2 +1/+1 ctr*
(U) Canyon Minotaur (3/3)
(T) Messenger Drake (3/3; Flying; When ~ dies, draw a card)
(S) Angelic Wall (0/4; Defender; Flying)
Graveyard: Soulmender, Mind Rot, Deathgaze Cockatrice, Quag Sickness, Oath of the Ancient Wood, Negate
Exile: Fleshpulper Giant (Psychic Intrusion)
=======================================================================
Mooseman: 13
Hand: 3 (Omenspeaker)
Battlefield:
(TT) Plains x2
(TTT) Swamp x2
(TT) Island x2
(T) Mountain
(TT) Forest x2
(U) Scholar of Athreos (1/4, 2B: Each opponent loses 1 life. You gain life equal to the life lost this way.)
(T) Agent of Horizons (3/2, {2}{U}: Agent of Horizons can't be blocked this turn.)
Graveyard:Time to Feed, Swamp, Coordinated Assault, Dark Betrayal, Traveler's Amulet, Psychic Intrusion, Leafcrown Dryad, Ray of Dissolution, Crackling Triton, March of the Returned
Exile: