You were the all powerful final boss also knows as the demon lord. You known for being the almighty and powerful demon known to man kind destroy armies and break magic shield with a flick of your fingers and ruled the mortal world with your loyal monster armies and servants but that faithful day the hero came…

With a brutal fight you lay down defeat with heavy injures and a sword pierced your heart. Your army was defeated by their allies but you dint want this to end. They might win the war but you started the battle!

With final magic words you casted yourself you turn to ashes your body was no longer with us but your soul kept living.

Thousands years later you been reborn into a boy/girl in a royal family as a human! Ever since you turn five you recall your past and all memory but casting them needs a lot of mana so your mana once a billion but now you are a commoner 50 mana, enough to cast one simple fireball. Reached the age of 10 you learned that your father Akira, he’s the bloodline of the hero who’s slayed you, and yes he’s a warrior while your mother Yokai teaches your magic seems she’s once was a holy maiden.

Over the years you see nothing change from adventures and guild handed out quests to complete from killing monsters, fetch or join other teams, that what changed was new spells, hybrids been born in this words form animals to other creatures, and countries with new kingdoms and arena.

Those the years you learned magic to 100, able to summon one big icicle. You need work even at this state you can able to be killed by one swing of a sword while your reflective on magic is high so no magic will hurt you but everything else will kill you.

You also got a little sister named Eri, she’s 6 years old and she’s mostly been with you when teaching and playing, sometimes she’s even joins you in the big spring and yes your parents are rich enough to buy a big spring in their mansion. But why is she’s so close you may ask? One time she watched you trying to summon a high level minion with 50 mana but failed making her fond of your powers and eventually leading her to following you around.

You are lying on your bed in your room trying to see what you should do, study to increase your mana to conquer this world again or enjoy your life in your royal family for a while in the medieval age.