Time to bring him back. I have posted this thought many times so...

A General decides he wants a super soldier to work for the government. Using New U's cloning process and a DNA sample from Flash before he ever put on the Venom symbiote they grow a new Flash. They then transfuse blood from William Burnside (Cap of the 50s) and the Super Soldier Serum stabilizes the cellular degeneration. They even scar Flash's legs so it looks like he has had limb transplants. As legally dead...Flash is now a ghost (figuratively speaking) in the world and is sent on missions that are too high a risk for even special forces units.

Until Flash realizes he is being used and breaks away