Change the Cloud card.

It is now part of escape decks and surrounds enemies with clouds, ranging
from mephitic to miasma.
Add draining to the Banshee card.
Add malmutate to Degeneration card (theTower).
Add Ephemeral Infusion to Elixir card.
Let Helm card protect allies (theTower).
Let Tomb card place walls on stone stairs.
Let Tomb work on deep water.
Change Velocity card.

It should always potentially benefit the player (if allies are present).