Think about it this way.
You spend 6
to destroy a creature. I think that this is valid in and of itself; if it doesn't seem good to you, I will increase the cost by 1 to make it 7
. Seriously, it's not that overpowered, but...
Next, at the cost of a whole turn's delay and the amount of quanta that the card actually costs, you may play the creature you just destroyed. This is a pretty hefty price, but it's worth it.
All in all, this card is not overpowered, methinks. But if you think the cost should be increased for the upgraded version, say so.