I'll assume you have proper reasoning for making the upgraded card different.
Absolutely. The difference is thematic; lakes upgraded to oceans.
I'd personally hike Purify's cost to around 3 . Minimum. Reusable Purify is surprisingly very powerful as you can create a very high regen rate. And screw many decks over aside from OTKs.
So, then, each use of Purify should cost as much as slapping down an upped SoG, for less healing/turn? Sure, it's powerful, but much less so than SoG, Sanctuary, or BH - all 3-Quanta healing, with extra abilities. Raising the ability activation cost to 3
would lower the hard-cast of the creature to 2
. Is that more reasonable?
For Oceanid, I don't like the ability at all. I'd remove the delay and make the debuff temporary. Or delay for one turn and debuff by -1|-1. As is, it's not exactly thematic and is OP in a sense.
Delay is thematic with SoP, Congeal, and Ice Bolt. I was looking at the ability as an Ice Bolt on a stick, with less total damage, but 100% chance to freeze for 1 less turn.
As is, I'd put the costs at 9|10. But with my suggestions, I'd say 5|6.
How does your figuring of costs differ by so much from mine? I'd like to know how you arrived at those numbers - was I missing something in my calculations?
Thanks for the suggestions!
Edit: missed a word