Complex sentence: While in the middle of testing the processor, Richard's son Seth returns home alongside his obnoxious band members, and overhearing his son badmouthing him, Richard deletes him, which retroactively erases his existence.
Split into simpler sentences: While in the middle of testing the processor, Richard's son Seth returns home alongside his obnoxious band members. Overhearing his son badmouthing him, Richard deletes him, which retroactively erases his existence.