light/ice mix is for hybrids  
 if you seperate light and fire
If you have an attack rating that outclasses your opponent, 
light will get you higher damage than fire 
because of the mag. attack +% buff.
If you have a very low attack rating however, 
even ice imbue will be stronger  
because of the huge damage spectrum 
 So 
light does extremely well vs monsters but needs work vs playersbut fire will give the mag. defense and immunity and a steady damage output, slightly less dependant from attack rating/parry rating.
So 
pvp --> fire/ice for good damage, defence and immunity
pve --> light/ice for good damage, speed and parry