Verified answer

I don't know who Yaldabaoth is originally written in Apocryphon of John.

That's not Greek, it sounds Jewish.

Yaldabaoth can be written usung the Greek alphabet like: Υαλνταμποαθ.

d sound is ντ in greek, b is μπ and th is θ (or δ but not in this case).

It could be Υαλδαμποαθ, sometimes δ is mistakenly written as d

"Children of Void" in Greek is "Τέκνα του Κενού" or "Παιδιά του Κενού", "τέκνα" is the archaic "παιδιά".

"Sons of Void" is "Υιοί του Κενού".

Also Δημιουργός (Demiurgus) means creator in Greek

Απόκρυφον (Apocryphon) means cryptic

You may find this interesting:

http://www.explorefaith.org/ford/ehrman2.html :

...She has named him Yaldabaoth, a name reminiscent of "Yahweh, Lord of Sabbaths," from the Old Testament, for this malformed and imperfect divine being is the Jewish God.

According to this form of the myth, Yaldabaoth somehow manages to steal divine power from his mother. He then moves far off from her and uses his power to create other lesser divine beings-the evil cosmic forces of the world-and the material world itself. Since he is the creator, he is often called the Demiurge (Greek for "maker"). ...

According to the Wikipedia article, the Greek name is 'Demiourgos' (Δημιουργός).

However, if you're looking to spell Yaldaboath phonetically I'm not sure whether your version would be correct or not.

The TH sounds have their own letters in Greek:

TH sound in 'think' is theta <θ>

TH sound in 'this' is delta <δ> (also used to transcribe D)

Knowing this it might be: Υαλδαβαοθ