Spin-off adaptations meant to tie in with their original source material can often have issues when it comes to being able to stand on their own as solid pieces of storytelling. They can easily end up inaccessible to all but the most hardcore of the source material's fans, and can just as easily end up bothering said hardcore audience.

Sekiro Side Story: Hanbei the Undying, a manga inspired by the hit video game Sekiro: Shadows Die Twice, is able to avoid these pitfalls. Even with its non-linear structure, the story enough to understand even if you've never played the game, and the way it delves into characters barely explored in the game makes it fresh enough that hardcore Sekiro fans have reason to give the book their attention. It's not a deep volume, but it's an entertaining and solidly satisfying one.

RELATED: Act-Age, Vol. 1 Subverts Shonen Cliches With Its Unnerving Protagonist

The book's main character, Hanbei the Undying, is secondary character in the game, a samurai cursed with eternal resurrection every time he's at the brink of death. The manga delves into his backstory, and the grotesque experiments which have granted him this ability and turned others less fortunate than him into "red-eye" monsters. Samurai action combines with magical fantasy elements and body horror in a compelling alternate history that feels both gritty and heightened.

Sekiro Side Story Hanbei the Undying 1st page

The characters are archetypes you've seen before, but they're appealing ones. Hanbei's like many an angsty immortal, while Shoukichi's the young hero who's willing to fight and sacrifice inspite of his obvious fear. Perhaps the most compelling antagonist in the manga is Yamahito, a disturbed hunter who fit in neither with the humans nor with the monkeys of the mountains, and who has a very memorable encounter with the Guardian Ape boss from the game.

RELATED: At Night, I Become a Monster Is a Poignant Meditation on Bullying

Mangaka Shin Yamamoto has experience in writing manga spin-offs of video games, having written a Monster Hunter manga among others, and his artwork impresses. The detailed artwork strikes the right balance between the realistic visuals of the game and more stylized manga art. In general, the younger characters have more stylized designs than the older ones, but expressive faces across the board . Action scenes are engaging visceral.

All eight chapters of Sekiro Side Story: Hanbei the Undying were previously released online for free by Yen Press, but all but the first chapter have since been removed. As such, if you missed that initial release and want to read Sekiro: Side Story, you can buy the collected edition in either paperback or digital download. While it's by no means an essential read, those curious enough about this manga to make the purchase will find much to appreciate.

KEEP READING: 7 Video Games That Need Anime Adaptations