Reborn as a Mountain: I Defy the Heavens with a Smile - Chapter 1: Reborn as a Mountain!

He was straight.Even after dying and waking up as the protagonist in his sister’s BL web novel.He was straight.Even with all the male leads practically throwing themselves at his feet.He was straight.Even when his heart inexplicably skipped a beat during romantic moments with one of them.He was straight.Even now... when he could somehow get pregnant.He was straight.There was no denying it.HE. WAS. STRAIGHT!“So, can someone please help me get out of this goddamn novel already?!”[Warning: 18+ content and there will be some themes of non-consent, mentions of abuse and suicide.]

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

The protagonist is an accidental time traveler - he didn't wait, didn't guess, only dreamed, but ended up in history, which he didn't pay much attention to. He was just lucky with his lineage.Ryo is a new member of the Nara clan, from the Uzumaki lineage on his father's side, and it so happened that he was born not at the beginning of the known plot, but more than three decades and two world wars later. Now he has to figure out how to get out of this situation however he can.

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates