I’m Not the Final Boss’ Lover - Chapter 21: Castle Tour

While the demons were rising, mankind was about to become extinct. Six temples rose and protected the last territory of mankind.

A young boy joins the temple as a knight to save his mother. During his journey full of miracles and tricks in the world where temples and demons are antagonistic to each other, will he be able to ascend to the strongest knight and inherit the sealed divine throne?

- Description from novelupdates

Stranded in a world not his own, in a body not his own, Kaden finds himself stuck as a low rank marine in treacherous waters in the middle of an ocean where only the strongest can survive and a count down until a war that would shake the oceans and the very world itself erupts, where the kings of the sea will devour the chum. Gamer System. Insert.

[Ding!][Ultimate Tycoon's Perfect Life System Activated][Spent $100,000 in an hour. 10x reward unlocked. Earned $1,000,000][Make the Villain beg for your mercy. Get premium limited edition super car][Destroy the hero who tried kill you. Get a villa worth of $500,000,000][Become the ultimate tycoon]James was an orphan has never had any luck in life, but that changed when reincarnated in his favourite novel, and got the best gift a reader could have get.“Do you want a perfect life?”The moment he accepted he transmigrated in his favourite novel and woke as poor character who got off-screened by the author.But the story he knew isn't the same anymore, the characters have their own free will, villain's may become hero's, hero's may become villain's. Constantly trying the damage the original plot he knew.But as a veteran reader how could he lose?No matter what happens he will protect his waifus, he will thrive, he will rise. he will become the “Ultimate Tycoon”

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?