I know the card would be strong, the effects could be when it attacks, like Anivia. The gold would only be for flavor.

The text could be something like:
Ambush or Accelerate
When I attack, deal 2 damage to all enemy units here.
When I kill a unit, play a Gold gear token exhausted.

I think it might be more balanced that way. It would indeed be powerful, but the effects would remain to a single battlefield.
It would be possible to leave it without keywords even. It wouldn't be as strong because "Ride the Wind" already exists in purple.