why not change it to a defensive permanent?
all water creatures (both sides of the field) become immaterial and gain momentum (no plus damage, just the effect)
How is that defensive? It sounds like a nice offensive boost to all water creatures. Maybe if you made cell death not count for bonewall, it would make it more powerful, but not extremely powerful.
@Mifurre: So you think having a permanent that can freeze 50% of all attacking creatures is a good idea? So you must've forgotten about Permafrost Shield that adds another 30%. That'd be so OP I didn't feel the need to tell you why when I said "think before posting".
50% chance to freeze for 1 turn is actually worst than Turtle Shield and much more costly, i don't think it's OP
With the same unkeep cost you can virtually disable 4 creatures at your choice for the rest of the game.
And btw your opinion to me is completely useless so don't even waste your time trying to argue nothing.
It's better than turtle shield because it's not a shield, so it stacks with permafrost, for a whopping 65% chance to freeze something every turn. And it would stack.
I can see quantumT's argument, but maybe a 40% starting chance and every other one raises the chance by 15%, then 10%, then 5% and so on. So it would look like this.
W/o shield With Permafrost shield
1 - 40% 1 - 60%
2 - 55% 2 - 70%
3 - 65% 3 - 75%
4 - 70% 4 - 80%
5 - 72.5% 5 - 82.5%
6 - 75% 6 - 85%
Sounds broken right?
But when you combine it with a 18
upkeep, it's somewhat in perspective.
I still don't like it as an effect however, it doesn't fit the theme of the card itself
My thought would be:
Drowning is a not an instant thing, all creatures can hold their breath for some limited time. What if it would be made something a bit similar to plague/thunderstorm? The cost and upkeep would remain the same, but it would flood the entire field (both sides) and make all the non-water/neutral (malignant cells were actually vulnurable to it when the card was introduced, and it turned out it was waaay OP that way in synergy with bonewalls and such) creatures lose, like, 1 hp per turn. Thus, with the 'recent' introduction of airborne creatures, they could be made immune to the effect too, because the fact that they're actually flying, and could easily avoid a thing like this.
This way - by looking at the relatively high number of airborne creatures, and the health of most others - it wouldn't be that overpowered, and would force the water player to keep up producing the 3 per turn and the opponent to actually take the permanent seriously and try to get rid of it. I think it can fit in with the defensive/offensive theme of water, and would find it's use even against the nowadays so common few-creature-setups.
As to this, it could work, but again bonewall synergy would be big as well as boneyard and soul catcher.
Maybe also make airborne creature lose 1 health if they dive?