Maharaja rakshasas are the apex of that vile race—creatures so evil and decadent that not only have they reincarnated as fiends, but also mastered the cycle of lives adeptly enough to climb to the very top of the rakshasa caste system. The Bestiary 3 goes into great detail about maharajas and their natures, so I’ll just add one final thought: While there are numerous other CR 20 fiends (pit fiends, balors, etc.), one of their hallmarks is that these monsters dwell in remote planes far removed from the realms of man—in fact, gaining easier access to the Material Plane is often one of their obsessions. Maharajas don’t need to reach across time and space—as native outsiders, they already walk among mortals, free to enchant, manipulate, enslave, and spread their evil at will.
An army of jotund trolls is approaching. The norns have predicted a defending force of heroes will rally and drive them back. But the steel-winged angel predicted to lead the countercharge is half a world away, chained in a maharaja’s seraglio. She needs a rescue—and sometimes prophecy needs a helping hand.
A maharaja has stolen the secrets of urdefhan soul harvesting and clockwork technology to build the Engine of Fate. Part of the maharaja’s bid to mount the next level of the rakshasa caste system, this monstrous minor artifact will not only pulp samsarans in its gears, but also rip their souls out of the cycle of reincarnation in the process.
The Kingdom of One Thousand and One Forms is known far and wide as a land of monsters, where the nagaji and minotaur natives rub shoulders with a dizzying array of humanoids and intelligent monsters that beggars description. What is not commonly known is the reason for this profusion of diversity—the secret monarch of the land is a human, snake, bull, and crocodile-headed rajadhirajas. By sending dandasukas to neighboring lands to quietly recruit cripples, lepers, the fatally ill, and other sufferers deemed untouchable, the rajadhirajas has amassed a fanatically loyal army happy to fight and die for the lord who has already rebirthed them once.
—Pathfinder Bestiary 3 226–227