Shadowforce was created by Kurt Busiek and Pat Broderick in 1994 and first appeared in Spider-Man and X-Factor: Shadowgames # 1.
Shadowforce weren't really locals. They were the government-owned creation that they were experimenting on convicted criminals.They were only meant to be test subjects. No special power except they were wearing a harness that temporarily the wearer body chemistry...granting induced superpowers. They were doped up and brainwashed so that the government can send them out to kidnap super-type, anyone but known mutants...who born with their power. Only so they can be scanned and studied to help stabilize the Shodowforce process which it never happened. That's when they face spider Man and the X-Factor. They were defeated except Hardtime. At the end of the section, they survived and pretty much walked away. But they never show up after Shadowgame 3.