Please forgive me for being a noob. Please help me understand. How is this not a toss up? Zhp is said to be able to change the past. Also I think parallax may be nigh omni-durable. The wrath aspect of of the presence, spectre, failed to stop zhp. whpotc is said be able to create a new future. It's also said that phoenix can destroy the universe can create another one. They didn't say she was omnipotent, but by being able to do these things they might have written her to be by accident.
I feel like no one wins, but if someone did I'd have to go with zhp. Only, because of the ability to write history. Although, It might be a stalemate, because I don't know if that would be enough to beat whpotc. Btw, I pretty sure zhp is capable of destroying everything too, he just can't rebuild afterward.