My thoughts, in no particular order:
-Names add a lot to the aesthetic of the card and since you cannot find a good mechanical reason to put this card in any one element, use the aesthetic. With it's current name, it's a little ambiguous. If you called it Enraged Frenzy it is a
card, but if you called it Thunder's Burst, I'd say it was
and so on.
-Looking at the details of the mechanics, we might have a good mechanical reason to assign it to any one element after all. It doesn't harm itself with this attack, so the self-sacrifice of
is out. It does harm your own creatures, I assume, so
or
might use it. Though Death already has a mass damage card, thinking about it, so it's out.
-You say
or
would benefit from it in the meta, so those are good options. While we're looking at deckbuilding,
and
already have mass effect cards (though not mass damage per se for
) so set those elements aside.
The argument for
,
,
, and
you present is probably the one that matters the most, overall. Earth would take my vote because the image of little rocks flying everywhere is the one that sticks out in my mind the most. That might inspire the card art?
