Remove the Heavy Destroyers, and Scarabs. Keep the Immortals, but try make it a ten man squad. The Necron Lord should have Veil Of Darkness and use him in conjunction with the Immortals. Don't give him a Warscythe beacause he can't shoot, and dropp Phase Shifter. Use the Wraiths and Flayed ones together, by moving the Wraiths foreward then deepstrike the flayed ones behind the enemy your Wraiths are going to assualt and have fun from then on in. Also if you want to make a larger army, More Warriors and A MONOLITH.