Mal'damba is the best healer for duels, if the Androxus is foolish enough to get close to you where you can comfortably hit your shots and the reload stun you CAN win, but if he doesnt good luck waiting for respawn.
When an Androxus activates Reversal and you have fired to much already, dodging around makes you a much harder target to hit. Also, if you want to deal damage, and you have an AoE attack ability, aim slightly in front or to the side to hit him.
Try to make him waste his ammo, catching him on an empty mag is like catching him with his pants down. Try to make him panic and use reversal leaving him vulnerable. Don't track him through his dash place your crosshairs at the destination.
While Androxus is channeling Reversal, take the time to reload your weapon, switch targets for a moment, or escape if needed, as it's detrimental to you to attack him during this time.