WU's Stifle and Wasteland pressure your mana and triggers: Stifle can counter fetchland activations and triggered abilities like Narcomoeba or Bridge from Below, and Wasteland punishes your nonbasic lands. Their threats are Tamiyo, a flier that fuels card draw, and Phelia, which exiles a potential blocker when it attacks, so your ground creatures don't hold them off well. Into the Flood Maw gives you a cheap instant-speed answer to Tamiyo's creature side, Phelia, or Quantum Riddler by bouncing it to buy time. If you promise the gift, it can also bounce any nonland permanent, including a flipped Tamiyo, but they get a tapped 1/1 Fish. Golgari Thug and Poxwalkers don't advance your plan fast enough against their counterspell suite, so trim them for interaction. Silent Gravestone stops cards in graveyards from being targeted, which blanks Snapcaster Mage's flashback, Mystic Sanctuary, and Tamiyo's -3. It also stops your own Dread Return from targeting, and as a colorless spell it can be countered by Consign to Memory, so treat it as a minor inclusion.