If you're using a low impact rifle then stay away from corners. Everything beats you at close range. Just grind ROC playlist for better weapons, like a void fusion rifle or shotgun and a rocket launcher. Defender is bad for PvP. Your grenades are below average, melee skill is short range, your super is just a target for every other super. Better to use striker and be a shoulder charging shotgun noob than having a low kd with occasional void melee kills.