This aside, the map Orcus left were actually locations where he hid his corpse armies.
After a Death God's death, it obviously followed suit that their constitutions' world would collapse. If this happened, then all of the corpses Orcus had painstakingly refined would disappear.
Dyon wondered for a moment why he hadn't just kept the corpses with him, but in the next moment, he understood. Orcus didn't want to stagnate while he was in this world. So, he left his corpse army in places where they could be slowly strengthened over time.
Although Orcus was a Higher Existence, none of his corpses had been. Refining a Higher Existence puppet was just too difficult. Even the mighty Elvin Kingdom which Orcus feared so much could only guard their tombs with peak dao Sentries.
Orcus hoped that by allowing his corpse army to be refined over trillions of years, he would eventually break the innate limitation of his corpses and allow them to enter the Half-Step Transcendent realm.