Ok, so I seem to remember another card idea recently that was something like this, but for creatures. (I'll put in the card picture soon. btw, I need art.)
So I've been using time recently and I'v realized that it could use some kind of PC. (this is a spell, just in case you were confused)
Age | Decay
2
3
After two turns(opponent's), target permanent is destroyed
Upped: Target permanent is delayed for one turn, then destroyed
I just thought it would be an interesting mechanic. The unupped cost as much as reverse time and doesn't work as well as deflagration. The upped acts sort of like a viridium warden for permanents.