The Rei Emperor named Erkin was renowned for his tyrannical ways. He was originally not destined to rule after his Father Emperor because he was not favored by him. He was also the son of a lowly concubine who couldn't even receive a proper title after giving birth to a son with the former emperor.
His life after being born was naturally not straight and easy as he was constantly suppressed and even experienced countless assassination attempts which, every single time, he almost didn't survive.
Thankfully, he was able to evade and escape with his life still intact. Forget about the fact that he was injured seriously every time. At least he still lives.
However, even being a prince was not at all beneficial to him as the former Rei Emperor even tried to kill him because he abhorred seeing this son of his becoming more prominent as he grew.