Pentweret vs Demdemeh ability

Can Pentweret steal an ally, that moved to play by Demdemeh's ability?

Pentweret
Independent: When in combat at close range with an ally that costs less than 4 blood or pool or a vampire with capacity less than 4, Pentweret may give you control of that minion as a strike that costs 2 blood.

Demdemeh
Laibon: If any Gehenna cards are in play during your unlock phase, you may move an animal retainer on Demdemeh to your ready region as an animal ally with 1 strength and 1 bleed. While that animal has more than 2 life, he or she gets +1 strength.

Because the cost of the ally is not defined. Or in this case, it counts as zero?

Keiran wrote:

Because the cost of the ally is not defined. Or in this case, it counts as zero?

Retainer cards that Demdemeh made an ally have costs (varies depending on card obviously). Is there a reason why those wouldn't count? It has a cost, it now counts as an ally.