(
: Add
or
to your mana pool.)
At the beginning of your end step, if you didn't cast any spells this turn, Flood Cavern deals 1 damage to you.
,
: Target land becomes a 2/2 blue Cephalid creature until end of turn. It's still a land.

,
, Sacrifice Flood Cavern: Put a -1/-1 counter on target creature.