The only annoying thing I see about this card is that it is essentially a trio.
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to play
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to activate and
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to use the hourglass effect.
Normally I would say thats bad, because I think cards should be thought of in element with an off color mark first and formost, but hourglasses are predominate in rainbow decks so I suppose it couldnt hurt. I just dont think this card would see much use.
6 quanta and 2 turns to play an hourglass, and 5 of that quanta may be wasted by the permanent being destroyed.
Personally, I think it would be better as a high HP creature like 0|15 or something like that, so that it would have more uses. Right now all it does is allow for more than 6 hourglasses in a deck (which I dont see why more than 6 would even be needed). If it was a creature though, it could be used as a catapult fodder (this is used in a rainbow anyways), or a buffing target when you need it, and an hourglass when you dont.