Mono-White Aggro floods the board with cheap creatures and tokens from Battle Screech and Novice Inspector, then threatens to end the game in one attack with Guardians' Pledge or Prismatic Strands protection. Arms of Hadar is your best answer to swarm boards, wiping out the small utility creatures that fuel their engine. Unexpected Fangs on Sneaky Snacker or Spellstutter Sprite gives you a lifelink blocker that can stabilize against their burst damage while keeping pressure on. Trim the clunkier cards like Gurmag Angler and Deep Analysis since the game is decided early, and cut Spell Pierce since their key spells are sorceries and white removal. Keep Counterspell up for Guardians' Pledge and Prismatic Strands, which are the cards most likely to blank your board stall.