It would seem the most interesting for it to produce both
and
after each Thunderstorm. This version allows for perfect trio and even duo synergy.
Also, I'd argue that this card could replace Thunderstorm entirely. *whistles innocently*
As for the name, maybe calling it Storm Shield and having it be a shield could work? Also, maybe the upgraded one could block 1 damage. If you need to condense your text you could write "At each turn where your HP < enemy's HP, casts a Thunderstorm"
Nice card Atico!
EDIT: By the way, what's the policy for using someone else's photos. Isn't that intellectual property? You might want to ask a Card Curator. Try your hand at drawing. ^_^