As a Necron player, the advice given already is solid. AP4 is great against Warriors and the rending chance + higher strength makes it worthwhile against Immortals and the Spyder.
As said before, ensure that he is playing the Decurion correctly, as the Destroyers and Barge are out of place if this is a decurion list. That said, the Canoptek Formation can be added into a CAD as it is a formation that can be allied in. Just ensure that he isn't trying to get the +1 Recon bonus for his army.
Wraiths will always be tricky due to their saves and newly acquired +1 T. Vindis can get lucky and ID them. Infact, high strength/low AP is good in general. I will say I hate going up against massed Plasma from my friends own DA. My friend even makes decent use of the Landspeeder Vengence, though I am quite aware of it's downsides.
As said before, ensure that he is playing the Decurion correctly, as the Destroyers and Barge are out of place if this is a decurion list. That said, the Canoptek Formation can be added into a CAD as it is a formation that can be allied in. Just ensure that he isn't trying to get the +1 Recon bonus for his army.
Wraiths will always be tricky due to their saves and newly acquired +1 T. Vindis can get lucky and ID them. Infact, high strength/low AP is good in general. I will say I hate going up against massed Plasma from my friends own DA. My friend even makes decent use of the Landspeeder Vengence, though I am quite aware of it's downsides.