crem is two card combo for, as you said, seven fire and one nova
sponge + nova are two cards that can can be played independently. in the wait one turn scenario manuz brought up, these two cards yield a total of five water and one nova.
i believe these two cases are more or less balanced, as while sponge has the independent card thing going on (with the high probability of nova not being used in order to create more focused water deck) and the possibility of yielding greater quantities of water with longer waits, its vulnerable to cc and requires seed quanta to put on the table
on the other hand i have often heard people say that they find immolation really detrimental to the game. would another immo-like be a good addition to the game? people often also complain about how cheap and powerful cc also hurt the game- fast water rushes would only empower them more
on the other other hand water cards arent really great rush cards
eh i dunno this card seems p cool to me
edit: the only thing i dont like is the "gain arbitrary bonus when in flooded area"mechanic. seems really forced to me in this and other cards.