The parents of Luke Frost were Jehovahs Witnesses; his father, a minister in the Witnesses, died of cancer by refusing to have any medical treatment; his mother, daughter of a Witness minister and editor of the Watchtower, who had prayed and knew God would save her husband, and was in extreme trauma after He didn't, ran off in the night during a thunderstorm some time later.
Luke developed powers in the trauma of his fathers death and mothers disappearance - he was fifteen (at the same time his sister Tracey, then aged seventeen, also developed powers). They repudiated the Jehovah's witnesses and became Crossfire and Rainbow, feeling a duty to help people.
After 6 months of minor crime-fighting, in 1987 Dr Destroyer turned up looking for them. He defeated them casually, leaving Crossfire for dead and carrying Rainbow off.
Luke lost his memory and knowledge of his powers and wandered about for a while before being taken in by Emily Wright, a sweet old lady who was also once the supervillainess Lynx (unknown to Crossfire). She gave him the ring he carries to help him in case of need (it was an experimental weapons system she had stolen from a the New Frontiers Corporation in 1936 when she needed more cash due to her fortune being wiped out in the Great Depression, and felt she needed the edge the ring gave as she was getting old).
Meanwhile Rainbow was being twisted into Anguish by Dr Destroyer. A few months after getting the ring Luke returned home to find Emily being beaten up by burglars; he started using his powers to beat them up , defeated them and had them arrested.
Crossfire is not such a nice person now, despite trying to help people. He thought all his powers were from the ring until he regained his memory upon meeting Anguish, when she recognised him. She hates him as she thinks he left her to Dr Destroyer (actually due to Dr Destroyers warping her mind). He lost the ring when Vindicator (Alan Fitzwilliam), descendant of the man Lynx stole the ring from, came back and took it from him. He wandered off alone to try and get it back, but failed. He hasn't been seen since because, when Dr Destroyer appeared in Times Square in 1990 he concealed himself on the Doctor when he teleported off and eventually blew up his orbitting fortress. His fate is unknown...
Crossfire's intrinsic powers were the ability to shrink to tiny size, and fly while in his shrunken state. Through his ring he could fire several different kinds of energy beam, and direct energy to heal a target. Unknown to Crossfire, Emily could still control the ring if necessary, without touching it.