Everything except the maiet edits are (quite likely) rips from different sources (read games) based on the jump the model and texture quality does.
The npc of "his" is the puppet that the skull kid spawns in legend of zelda twilight princess for example.
More than likely the skills he possesses is presented by his maiet weapon edits, ripping and re-exporting isnt what i define as a skill.
I applaud you for applying a simple idle animation to the puppet model but thats about the extend of it for me.
For example if the 2 example sets were made by him from scratch and everything you wouldnt have a random **** up like this which is wrong triangulated quads, this hardly is the fault of sketchfab as the model is mirrored meaning it would be the same on the other side but that isnt the case.
The female variant's parts arent aligned properly and has similiar (albeit not as bad) triangulation issues in the armpits, again stuff you would catch and fix if he were making them from ground up, i would at any rate.
I know he said his english isnt great and where he is from but half the stuff he is writing is incomprehensible word salad, which is a little problematic for teamwork if we cant understand what he is trying to say half the time.
Its hard for me to believe his claims of "work with official companies" with what he presented thus far.
And by pointing all these things out im going to come of like the biggest asshole.