So I guess damage can resolve since you're out of cards.
Thallid and Sphinx die, Fallen Ideal returns to your hand, you take 1 from the Looter, it's ability triggers, I draw a card, I discard a Swamp.
Island
Done - Elemental is sacced
boogiepop: 7
Hand: 1
Library: 26
Battlefield:
(T,U,U) Forest x3
(T,U) Swamp x2
(S) Thallid Shell-Dweller (0/5, Defender, At the beginning of your upkeep, put a spore counter on Thallid Shell-Dweller. Remove three spore counters from Thallid Shell-Dweller: Put a 1/1 green Saproling creature token onto the battlefield.)
(U) Contagion Clasp (When ~ enters the battlefield, put a -1/-1 counter on target creature. 4, tap: Proliferate.)
Graveyard: Swamp, Forest, Deathspore Thallid, Thallid Germinator, Thallid Germinator, Savage Thallid
Exile:
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Spiderman: 16
Hand: 0
Library: 23
Battlefield:
(U,U,U) Swamp x3
(U,U,U) Island x3
Gibbering Descent (At the beginning of each player's upkeep, that player loses a life and discards a card.; Hellbent - Skip my upkeep step if I have no cards.; Madness 2BB)
(U) Aquamoeba (1/3; Discard a card: Switch ~'s power and toughness ueot)
(T) Looter il-Vec (1/1; Shadow; Whenever ~ deals combat dmg to boogiepop, draw a card then discard a card)
Graveyard: Looter Il-kor, Rootwater Depths, Island, Hapless Researcher, Gorgon Recluse, Vexing Sphinx, Swamp, Brackwater Elemental (Unearth 2U)
Exile: