By the same artist as
http://www.theprocess.cc/forum/showthread.php?t=1756
This has been floating around for years, but I recently came across a copy of Ketsu! Megaton Z (where it was originally located) and decided to post better scans of it here. There's a chance another version is posted in these forums somewhere, but a quick search of "gladiator" and "jun" didn't turn anything up.
Anyway, most of you probably won't like this, so this is for the few that do.