on your other reply on another post you said that you already played Z7 right? you said..
"a: ive played z7.\\\\ b:u only need legend achieve to get to z7 c: u cant get to z7 in challengeing altogether, even if u got legend."
so since you already have, why have trouble with these opponents?? why dont you just train for another level or 2, then you could kill them easily.. there is no point to not train since you already acquired the legend achievement as what you have said in another post..
Nice fail quadruple post, anyways I beat this on heroic and even on a higher level I don't know how it's so hard, just figure out a good strategy or find one in the forums.