Holy shit Dory Funk!
Also, holy shit, author of the world famous manga, Dogesen, Itagaki-san!
Honestly, not shocked he self-inserted as jacked considering the universe and considering shit why not right? Also, is he supposed to be The Augor, or did someone make a woopsie?
HEY!!!! Dogesen is not Itagaki, how darest thou. Shaman and Dogesen were intended to be a single manga as a collaborative effort between Itagaki and Kasahara Rin, but they ended up each doing their own separate manga due to "disagreements over the philosophy of dogeza" (yes, really). While Itagaki is credited as author for Dogesen, it's more of a credit for the original concept. I may be wrong though since there is a sequel to Dogesen titled Dogesen R, which may be the result of the friendly disagreement on Kasahara Rin's side. I can't quite recall, but regardless, there's some trivia for you.
Also, it's not a self-insert but one of Kenji Hamaoka's characters from Super Radical Gag Family, Itagaki is pretty humble when it comes to self portrayals. As for "Augor", I'll paste what I wrote under the reddit announcement:
It's intentional. The original kanji is 画王 (art king), with the reading ガオー (gaō) which is オーガ (ōga), Yuujirou's epithet as The Ogre, flipped. One of the authors behind this, Hamaoka, is notorious for these kinds of intentional puns in his manga Super Radical Gag Family.