Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Whenever Broodbirth Viper deals combat damage to a player, you may draw a card.

Flying

: Ribbon Snake loses flying until end of turn. Any player may activate this ability.

Flying

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)

Spire Winder gets +1/+1 as long as you have the city's blessing.

Yuan-Ti Malison can't be blocked as long as it's attacking alone.

Whenever Yuan-Ti Malison deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)