Alan’s consciousness has been buried deep by the Starheart, which is almost in adolescence as far as maturity goes. With new found sentience in Alan’s body, it seeks to carry out the directive of it’s creation…the elimination of chaos. Of course, Earth is mostly chaos, so elimination of Earth.
But how does it possess one of the most powerful metahumans in the DC Universe? By giving Alan’s subconscious enough wiggle room to create the facility and constructs, but not exert any true control. That’s why everything looks like stuff connected to Alan, it’s keeping him under control.
