Hello Dag!
Nice card you got here. I like the 1st version better, i think OdinVanguard suggestions are perfectly fitting, but i would modify the upped like this:
Unupped (stays the same as OdinVanguard said):
2|0 stats, generates
when played
Upped (-1 HP, +1 ATK, i prefer this since Water has SoP anyway, and you can use the wave itself to power it):
3|0 stats, generates
when played and an additional
after each turn
Also agree on
cost for the upped.
Sidenotes: i like this concept, especially for its flavor, perfectly fitting.
And: THIS HAS BEEN MADE BEFORE!