Doomsday is a fast combo deck that wins primarily through Thassa's Oracle after constructing a graveyard pile; Leyline of the Void in your opening hand is your best tool, as exiling cards instead of sending them to the graveyard completely dismantles standard Oracle piles. Disruptor Flute naming sorcery acts as a repeatable soft lock on Doomsday itself, forcing them to hold up mana every turn and buying you the time needed to assemble Painter's Servant plus Grindstone. Your full suite of Pyroblast effects and the additional Red Elemental Blast are premium here — they answer Force of Will, counter Brainstorm, and can blow up Tamiyo, Inquisitive Student before she flips. Lightning Bolt provides a clean answer to Thassa's Oracle in response to its triggered ability, functioning as a kill spell on the win condition directly. Trim the slower, creature-matchup-oriented artifacts like Ensnaring Bridge and Chaos Defiler that do nothing against a non-combat combo strategy, and prioritize deploying your combo before they can set up a Doomsday with Force backup.