Frieren: Beyond Journey's End - Uwooohhhhh

Gotta have a big lineage so Frieren never gets lonely

Set to NSFW because of spoilers

Honestly, I think that's a good way to end the story. Reminds how in the end of Tales of Graces, the protagonist Asbel adopts the immortal loli Sophie, with the post credits scene has her playing with and looking after Asbel's descendants.