i wouldnt say i cheesed it but i'll tell how i defeated her.
team :
dusclops : 252ev def/ spdef, eviolite
a- 9tails
luxray: 252 att, magical seed
hydreigon: 252 spatt,speed, magical seed
metagross: 252 att, magical seed
talonflame
sent out dusclops and a-9tails. dusclops used trick room. ninetails for hail. switch out 9tails for talonflame. both died this turn. sent out luxray and hydreigon. dark pulse on chandelure, wild charge on corviknight. metagross handled the rest from here. aegislash can be tricky but it will die too