@Grishnag
Well, let's see. I was mostly talking about the fact that I've seen all the major and most the minor elements used here before, but they were mixed in a fairly original way here.
The whole youthful but ancient and lonely Elf trope is absolute fantasy standard, even Tolkien already used that. As far as Mannga go, I remember a Record of Lodoss War manga that had this trope with a focus on Deedlit. Another One would proabbly be Spice and Wolf, while it's about the immortality of a God rather than an Elf I'd still count it as a fairly recent example. I think Goblin Slayer did some hints at this trope already as well, though that series has a largely different tone, so I can't really recommend it in regards to similar stories.
As far as the interactions between different species in regards on exploring the differeces of their nature go, and how they come to learn and accept their differences and each other. Another tolkien classic thatas far as Manga go, again is found in Goblin Slayer and Record of Lodoss War.
As far as the generational thing with different hero/adventurer parties over different decades with direct or indirect influence on each other goes, I'll just name Record of Lodoss War again,
And for the Sage with interest in odd magic, sadly I can't think of an example right now, though it did happen before.
For the small scale story of a personal journey, rather than one saving the world or somthing grandious like that, I'd say Spice and Wolf covers that again, as very recent work "Henkyou No Roukishi - Bard Loen" about the retired knight on a last journey also counts (which also has something of a slice of life feeling to it). I'm happy not having to name Record of Lodoss War again, since all the main series decide on the overly important motivations for their groups.
To make it short many of the themes here have been seen in Record of Lodoss War as well, and since that franchise was hugely sucessfull and influential in the late 80's and early 90's there were countless of copycat manga and Anime of varying levels of quality. But I don't really know them by name since it was before my time. This series certainly isn't coy about knowing Record of Lodoss war either (the Elf taking the booby trapped treasure annoying the other party memebers scene was certainly a deliberate nod to ROLW), but I'd say it's too original to be seen as one of the copy cats.