Yoshiyuki Sadamoto (貞本 義行) is best known as the character designer for Neon Genesis Evangelion, of course, but he has a long list of accomplishments as an artist.
He also, with Hideaki Anno, Takami Akai, Shinji Higuchi, Hiroyuki Yamaga, Toshio Okado and Yasuhiro Takeda, co-founded the Gainax anime studio in the early 1980s. Before it was officially named Gainax (it was originally called Daicon Film), Sadamoto worked as an animator on the the Daicon III and IV short films featuring a girl fighting monsters and robots, and even a daikon radish that turns into a spaceship. These two shorts were re-used as opening animations in the Gainax OVA Otaku no Video (1991). His first work as a character designer with Gainax was in Royal Space Force: The Wings of Honneamise in 1987. He worked as an animator on Gainax projects Gunbuster (1988), Nadia: The Secret of Blue Water (1990), and Diebuster (2004). Sadamoto designed characters for many projects, both with Gainax and others: from Nadia, Diebuster, FLCL (2000), (all Gainax projects), to .hack//Sign (2002), The Girl Who Leapt Through Time (2005), and Summer Wars (2009), to films like Wolf Children (2012) and the Rebuild of Evangelion series. In 2007 he was key animator for episode 27 of Tengen Toppa Gurren Lagann, and was both animation director and key animator for Evangelion 1.0 You Are (Not) Alone.
Sadamoto is the creator of the Neon Genesis Evangelion-based manga series, his first full manga work, which is an alternate continuity to that of the original series. He is also the author of the shorter 60-page manga Route 20 (1991), as well as the author of 2 short novels, Dirty Work and System of Romance. When he was 19, his manga work was published in the Akita Shoten weekly Shonen Champion. He decided to become a manga artist, he said, "[r]ight about the time I was in elementary school and middle school, Mazinger Z by Go Nagai, and Leiji Matsumoto's Battlefield manga series were just coming out. About that time I thought it might be nice to become a manga artist."
In 2003, Viz published a collection of his works, titled Der Mond ("The Moon"). Other artbooks like Die Sterne ("The Stars") and Groundwork of FLCL showcase his talent. He also did the artwork for the cover of Eric Clapton's album Pilgrim.
In an interview published in Der Mond, Sadamoto describes some of the brainstorming sessions between him and Hideaki Anno during the early development of the Evangelion project. Some of Sadamoto's ideas that ended up being used include: suggesting that Anno change the protagonist from a girl to a boy, favoring the name "Evangelion" over "Alcion," proposing the concept that "the dead mother is inside the robot ... operated by mental/psychical bonding with the child" after learning about the A10 nerve from a program on NHK, and making the show a TV series instead of an OVA.
In 2008, he produced a two-part manga called Archaic Smile with his mangaka wife, Mako Takaha, that appeared in Monthly Shonen Ace. At the 2013 Tokyo Anime Fair, Gainax announced that they would be reviving their Blue Uru film project, with Yoshiyuki Sadamoto as the character designer.