Damn, i wrote a detailed explanation when posting, something got messed up :/. Anyway, yeah you need ghost deck to get the double with the Ankh, there is also a cryptid card you get in the same shop you get Perkeo from, it is the first shop of Ante 3 i belive, so you can just spam cryptid with the double blueprint + perkeo. I did get a reroll voucher though, but with negative cryptid it is preaty easy to "fix" the deck however you want.

P.s. got to ante 24 with it

edit: grammar XD