Anu is not Satan's father. That is an allegory. Satan being son of the heaven (Anu) and the abyss (Nammu/Tiamat), Satan being an Anunnaki which means "son of heaven and earth"... what do you think all these mean? They are allegory to the fact Satan is a God, someone who completed the Magnum Opus. Anu is heaven, in other words the crown, the sky, the aither element.
Marduk (or Sammas in other myths) killing Tiamat is an allegory to awakening the kundalini. You kill the evil dragon, that is then resurrected as a good dragon and ascends to heavens. It's the same function as Apollo (aka Sammas) killing Python in Greek mythology or Ra killing Apep/Apophis in Egyptian mythology. Indra killing Vritra in Vedic mythology. Thor killing Jormungandr in Norse mythology. Susanoo killing Yamata-no-Orochi in Japanese mythology and so on. It has been explained before in some sermons.
This is about the Gods and the use of allegory: https://ancient-forums.com/viewtopic.php?f=24&t=3130