Jim Shooter

Starting his career as a writer for DC's Legion of Super-Heroes at the age of 14, Shooter eventually became Editor in Chief of Marvel Comics in 1978 (aged 27!). During his controversial (but very successful) 9 year run, he overlooked Claremont and Byrne's X-Men, Byrne's Fantastic Four, Miller's Daredevil and Simonson's Thor, among many others. He introduced the Direct Market with Dazzler #1 and the premium quality, Marvel Fanfare.

Mostly remembered for launching crossovers, initially with Contest of Champions and later, Marvel Super-Heroes Secret Wars. He later launched, less successfully, the New Universe at Marvel.

Finally moving on from Marvel, Shooter has helped launched numerous comic companies including Valiant, Defiant and Acclaim. He continues to release work today under custom comics company, Illustrated Media.

Here's a tribute to the man by Comics Alliance:
https://comicsalliance.com/tribute-jim-shooter/