Responses
No, all I know is that FT mangaka assistant currently doing illustration for most of the mangaka ongoing works including FT itself,
As for this artist, they dont do much illustration but they did this oneshot
https://mangaplus.shueisha.co.jp/titles/100403
I really like the artstyle. The artstyle of goofy parts reminds me of Fairy Tail, and the muscle old men remind me of Armstrong from FMA. I wonder if the artist worked as an assistant for those mangaka?