@ArisatoMinato while I would agree with Wolvenworks that the overall plot is rather easy to understand, I have to admit, it does feel like it's a sequel story, rather like how UQ Holder can be read without knowing what happened in Mahou Sensei Negima, but you miss out on so much (especially inter-character relationships) if you haven't read Negima (or like Boruto/Naruto...but I didn't wanna go there cause...it's Naruto...) anyways, that said, I think the beastman village bit was less about the old wolfie meeting Shin again and more about Shin learning about what happened in the world after he vanished and meeting the new wolfie leadership, and the bit about the fight to the death was just a way of showing off Shin's OP-ness and maybe a little bit of character development for the new wolfie leadership duo
also, he was only gone ~500 years from their perspective
...and personally, I'm still a bit confused as to Shin's exact relationship with the wolfie and these six devas, was wolfie another of Shin's "AI" companions from the game made real or was he serving under one of these other "six devas" players and merely knew Shin well? it's obvious he respected Shin's power for it's own sake and that Shin did his gear making and upkeep, but was that cause Shin was directly his master or was that just cause Shin was the blacksmith of the devas and did all their gear? ...or were the six devas Shin and 5 "AI" companions, in which case Shin plus Schnee and wolfie made up half of the six? but that all falls under those inter-character relation things left out from a sequel story category more than the gaping plot hole category (assuming this is actually a sequel story)