This card feels far too weak; Compare it to poison (which is arguably OP) or long sword (which isn't). 2 charges when a creature fails to attack should be enough.
I concur -- consider also it is subject to PC and has delay to get quanta for it, play it, then charge it up, and then discharge it.
dawn-
Do the charges store up on each Clockwork card itself or in a group on one Clockwork or in a large group off-of-any-card? Connected to that is this question: Can one Clockwork discharge ALL charges or only ones on that Clockwork?
EDIT: Yeah, dawn is not Kuro... huh