Japanese The impassable hero of death is a TS returnee from another world

Name: 死の勇者TS陰子は異世界帰還者である
Raw Link: https://kakuyomu.jp/works/1177354054922565264
NU Link: None
Why It Should Get Picked Up: (sorry for my english, I'm not english native
Not your everyday japanese LN, in fact looks like a korean novel.
The novel isn't dark, but it has some really dark moments.
Ruthless MC, he didn't kill anyone in japan yet, but his retaliaton is worst than death, much, much worst, trust me.
Original magic sistem, mix between holy magic and necromancy
Good world built
His former teachers are really cool

Description: Ing Reinforce is known as The hero of death. He was a former japanese and his soul was summoned to exterminate the demon king. As a result of being trained by countless masters, he mastered magic, ruled all the defeated monsters, formed an army and swallowed all the Demon lord's army in a spiral of violence and barbarism.
He defeated the Demond Lord and even the evil god behind him. However people didn't support the overkill and wished him going back to his former world.
He was sent back to Japan, however there was no body to return and his wandering soul possesed the body of a former classmate (girl) who was commiting suicide. Even if his body changes, his personality didn't change, the violent hero ranmpages in his former hometown to relieve remorse of his body's former owner.

(I forgot to say that the former hero was a man and he is now a girl)

 

I know TS is gender bender but what does TS stands for?

 

Should be transsexual. JP titles containing this term prove unusually helpful in warning one away.

 

Oh, sorry he moves from male to female, his shoul possesed the body of a girl who commited suicide

 

TS does not get confused with traditional games as TG does in google