His plight isnt all that hard.
1) acquire brainwashing magic
2) use it on the prime minister, first prince, queen, king, and then mein in that order.
3) have mein ascend the throne with the full backing of the royal family and prime minister
4) as the empire scrambles to start their next scheme, call for a friendly meeting to discuss their mutual futures.
5) brainwash the emperor. (Or turn him into a llama, whichever comes first)
6) bang the dark elf in every room of all the mansions
7) profit.