Doomsday wins by assembling a five-card stack and casting Thassa's Oracle; Veil of Summer makes us hexproof from black, so Thoughtseize can't target us, and it makes our own spells uncounterable for the turn against their Force of Will and Daze. Pithing Needle is weak here: Thassa's Oracle's ability is a triggered ability and Personal Tutor is a spell, so Needle can't stop either one. It only affects activated abilities, such as their fetchlands. Grafdigger's Cage is also weak here since their combo casts Thassa's Oracle from hand and doesn't rely on cheating creatures out of a graveyard or library. Two Disruptor Flutes come out to make room for Veil of Summer. Keep our full mana-denial suite since Doomsday is vulnerable to losing a turn of development.