So, correct me if I'm wrong, but I just need to post the ideas here?
If that's the case...
Aboleth: a famous psionic and acquatic creature.
Cost: 7
| 7
Stats: 0/5 | 0/8
Skill:
: Thrall - Target creature is delayed for a turn, and Aboleth gains attack equal to target creature's attack for a turn.
Explanation: any card that can reliably stall opponent's creatures - especially if resilient to CC - works well with Inundation. And this can provide a good finishing touch to a good combo. Also, Quinted Squids and Mind Flayers are what makes aether water good already.
Tsunami: no, not the Poseidon skill. Can be renamed as seen fit. It's a spell.
Cost: 6
| 5
Effect: underwater creatures' attack is doubled for a turn. Non-water, non-untyped creatures die if underwater. All remaining
quanta is expended.
Explanation: Who doesn't like Sky Blitz?Hellfire: a permanent that sets the field on fire.
Cost: 2
| 2
Effect: top/bottom row are on fire. Creatures in those rows and every player take 6 damages per turn. Doesn't work if field is flooded.
Explanation: both enhances terrain effects and increases the potential of Inundation overall. Not that intresting, I admit, I will think of something better soon.