Mick Rory aka Heatwave from the CW DC universe. He's currently a member of the Legends of Tomorrow. He's always been a good fighter, but became much more formidable after his training under the Time Masters, where he supposedly received multiple "life times" of training as a temporal bounty hunter. He's stalemated Sara Lance, beaten an incarnation of Vandal Savage, and defeated multiple armed ninjas despite being unarmed himself IIRC, just to name a few H2H feats.