I don't like the random targeting. I think an active ability would be better.
that depends though, think about it:
refering to its upgraded form, It has an attack of 7, most creatures in the game have lower hp than 7, The creature card would be too OP if one had the choice of which to destroy, remember its a creature ability; not a spell card, and imho, I think its already very powerful.
however this statement is only applicable if you are suggesting it to be a "choice" of creature rather than random.
