At the San Diego Comic-Con International in July 2009, Radical Comics presented a special preview edition of Simmons's own comic book, Incarnate, from the Simmons Comics Group. It was released August 1, 2009. In February 2010 accusations arose that Simmons had plagiarized character designs, fight scenes, plot segments, dialogue, poses and expressions from both professional and amateur artists, from several published manga, the most notable being Bleach, and from art communities such as DeviantArt. Simmons responded to the accusations by stating that the similarities between the two works was intended by him as a homage, saying, "Like most artists I am inspired by work I admire. There are certain similarities between some of my work and the work of others. This was simply meant as an homage to artists I respect, and I definitely want to apologize to any manga fans or fellow Manga artists who feel I went to far. My inspirations reflect the fact that certain fundamental imagery is common to all manga." Evelyn Dubocq, Senior Director of Public Relations at Viz Media, the American publisher of Bleach, stated, "We appreciate all our fans bringing this matter to our attention, and we are currently investigating this issue". On February 25, 2010, the publisher of Incarnate, Radical Comics, announced on its official blog that it would be halting distribution and production of Incarnate until the matter was resolved between all concerned parties. Production of Incarnate never resumed.
Simmons contributed vocals to "Hand of The King", a song from Bruce Kulick's solo album BK3 that he also co-wrote. Kulick had served as a guitarist for Kiss from 1984 to 1996.