I think fireflies are intended to be bigger than actual fireflies. And also use fire attacks. Or something. xP
I like this card, but not the theme. It doesn't feel very elemental-y to me. Have you considered, instead of a spy, maybe something a bit more fantasy-esque? When I think elements + seeking intelligence relating to the enemy... I imagine a general holding a spyglass, surveying the battlefield from afar?
I don't mean to be a jerk and twist your idea or say it's not good. Because it is. But making your idea fit the game generally makes it appeal more to the masses, and modern day human-esque ideas don't generally get many votes.
As for mechanics...Hm. I kind of agree with having 4 attack. Any more and it's too much, any less and this card becomes far less useful. I think the unupped version might be worth decreasing playing cost to 4
. Thinking about it, it's like... you're paying 4
for 4 attack | 4 health, which is pretty much the base for creature costs (see abomination), and then to use half of a precog, you're paying 1
repeatable (not limited by card copies / drawing a card / whatever). I'm not expert on this, but I think that sounds fair. The upped would be fine at 5
because It gets rid of ability cost I spose?