Karthus' Lair is a red, dusty, smokey and suffocating area maintained by blood radiation, which can lure lumicons and transform pix flakes to Warrior burdneates. Spirits are not affected by blood radiation
It was built mostly by "Blood radiation" which kills plants and desertifies the area, and if the area is evil enough, it can hold a smoke phantom that can oversee burdenates.
It took about 300 years from about 10300 BC for Karthus' Lair to develop the Smoke phantom. The completion at 10000 BC let Alphaverse War 1 start, and ever since then, Karthus was summoning burdenates with his moon.
When a-lpha looked across the pit to look for lumicons, Karthus' Lair was away from the pit and started attacking another.
Once the Pit where the alphaverse was built becomes completely stone, the Lair retreated to reposition the blood moon and came back in 1700 to summon The Copyright
This includes un-dispatched Karthium Bosses