Sekiro: Shadows Die Twice

During the late Sengoku period, the Ashina clan, led by Kensei Isshin Ashina, seizes a land rich in divine favor, including a foreign deity dubbed the Divine Dragon which can grant immortality through a bloodline dubbed the "Dragon's Heritage" and through the Rejuvenating Waters and its mukade-infested Sediment. During this time, a nameless orphan is adopted by the wandering shinobi Owl, who names the boy "Wolf" and trains him in his ways. As Wolf grows up, Owl entrusts him with safeguarding the young lord Kuro, the last of the Dragon's Heritage line.
Two decades later, the now-elderly Isshin is on his deathbed and the weakened Ashina is besieged by the forces of the Interior Ministry to finish the unification of Japan. Desperate to save his clan, Isshin's adoptive grandson, Genichiro, seeks Kuro to use his blood to create an immortal army. Disagreeing with his grandson's methods, Isshin has his private physician, Emma, warn Wolf so the two can flee. However, Genichiro confronts them and defeats Wolf in a duel, severing his left arm and capturing Kuro. Wolf is saved by a man called the Sculptor, who gifts him a prosthetic arm. To rescue Kuro, Wolf assaults Ashina Castle, where he meets Isshin and is given a new name: "Sekiro". Optionally, Sekiro can revisit his past through meditation using various items he finds; three years ago, Kuro's home was raided by bandits led by the shinobi Lady Butterfly, leading to Owl's apparent death. While Sekiro defeated her, he was fatally stabbed by an unknown assailant and only survived after Kuro shared his blood with him.
Sekiro again duels Genichiro and defeats him this time. However, he survives, having used the Sediment from the Rejuvenating Waters to gain corrupted immortality, and escapes. Afterward, Kuro refuses to flee and instead wants Sekiro to perform the Immortal Severance ritual on him, which would result in his death and eliminate the Dragon's Heritage. Sekiro reluctantly agrees and sets out to collect the necessary materials for the ritual, including a weapon that can kill immortals known as the Mortal Blade from the Divine Child – the sole survivor of experiments with the Rejuvenating Waters. After collecting most of the ritual elements, Sekiro is confronted by Owl, who faked his death in pursuit of the Dragon's Heritage and revealed to be the one who stabbed him three years ago. If Sekiro renounces his loyalty to Kuro on Owl's orders, he fights and kills Emma and Isshin while Owl kills Genichiro. However, Sekiro then becomes corrupted by bloodlust and kills Owl as well while Kuro watches in horror, leading to the Shura ending.
If Sekiro refuses, he kills Owl in combat and enters the divine realm to recover the final ingredient for the ritual from the Divine Dragon itself. Upon returning to the mortal realm, Sekiro discovers that Isshin has passed and Ashina is under attack by the Interior Ministry's troops who have set fire to the castle with rockets and flamethrowers. Fighting through the burning castle, Sekiro eventually finds Kuro under attack by Genichiro, who has retrieved another Mortal Blade. Upon defeat, Genichiro sacrifices himself using the second Mortal Blade to revive Isshin in his prime so he might restore Ashina, a wish that his grandfather attempts to honor despite disagreeing with it. After killing Isshin, depending on the items gathered, three endings are available:

In the Immortal Severance ending, Sekiro performs the ritual as instructed, killing Kuro and making himself mortal again. Afterward, like the Sculptor before him, Sekiro spends his remaining days carving Buddha statues while keeping his prosthetic to pass on to someone else one day.
In the Purification ending, Sekiro performs an alternate ritual worked out with Emma's aid which has Sekiro sacrificing himself while freeing Kuro of the Dragon's Heritage. Afterward, Kuro prays at Sekiro's grave with Emma before departing Ashina.
In the Return ending, Sekiro collaborates with the Divine Child to make her a vessel for the Divine Dragon's power. After defeating Isshin, Sekiro takes the dying Kuro to the Divine Child, who absorbs him into herself. The Divine Child and Sekiro then leave on a journey to return the Dragon's Heritage to its home in the West.