when it comes back from undying, copy a primevil titan. A lot of things have to come together. Like playing against ramp, who has cast a titan, who chooses to block it I guess. Or maybe slagstorm on the next turn? I honestly don't see either happening very often. Ramp player would have to be in an aweful situation.
If "Delver Decks" warp the metagame this much... Then Wizards... It is time to Jace it. Ban it now, let the format grow a bit.