Back onto the Necrons...
An interesting build is one filled with Wraiths, with a Destroyer Lord with a warscythe and rez orb flying with them with a Monolith in tow.
That Wraith Squad is ROCK hard to bring down, 3+ In with a double WBB? Thats insane... And they're bound to thin the attacks back against them with the I6m S6 and 4 attacks on the charge. While the warcythe can cut through pretty much anything.
Being Jetbikes means they'll close for assault pretty quickly and are a great means of contesting objectives towards the end of a game