Deep in the deserts and in dark underground places dark cults worked sculpturers into being. They prayed for salvation from famine and war but yhe emotions of hate, fear and anger was stronger and something answered the call.
These Pokemon accumulate cults, inducing psychosis and illusions of grandeur in affected populations. They feed off the ensuing insanity and evolve only when they hit a peak of the dark energies that surround them.
If a trainer wishes to evolve them into the strongest final evolution they need to reach a sect of cultist to envelope their Pokemon in the insanity.
But beware, you may be the one being controlled in the end.
by Insectdevil