Deliberate that you have to discard it? Nice name for a sneaky "you forgot this was 'in play' didn't you?" card. I dislike that sort of card personally.

As a common, this seems to risk that you'd get a bunch of them and no way to discard them.

Uncommon then? I don't think this card stands out enough to be "that bad rare."

Sitting until written over

Dunno, it's got that "Ok, you need to figure out how to use it" quality. Given which, maybe it could be a lot more damage and then be an impressive rare? As uncommon works for me though; presuming there's lots of discard in set.

Blegh, probably definitely too complex for common.

I don't think it's a bad card, per se, but that's way too high a cost. An artifact that untaps a permanent every turn costs about . I'd assume this very restrictive untapping artifact should cost and equip for .