Nobody. That's why He's GOD. He always was. He didn't need a creator.
If you rationalise a 0/0 division, any number can be proven to be equal to any other number. This is somewhat like that.
If the said entity has the characteristic of timeless existence, then why is the act of creation trapped in a time-based bubble? What time-based factor influenced the creator to create, from within a period of infinite time, at the particular instance that it did, so to speak?
There's a huge problem with trying to splice together concepts of a time-based reality with a timeless hypothesis.