Good morning all!
I have been giving a lot of thought to the Necron codex lately, trying to find synergy between units that may have been overlooked. There is nothing I enjoy more than being able to take a unit that is generally frowned upon, and making it into a viable choice when used. So I am going to share some of the ideas I have been bouncing around in my head. These thoughts were not formed with the tournament scene in mind, so please keep that in mind.
First up is the idea of using one or two 6 man squads of wraiths with whips, using the wraiths to pinch off a side of the board. Wraiths are relatively easy to get to the other side of the table with ignoring terrain and their 3+ + save. They also put enough hurt on units that they really cannot be ignored, and opponents usually dedicate a part of their force to take them out. Use the wraiths to try and pinch or lead the enemy to the side of the board, then outflank the flayed ones to decimate whatever was sent after the wraiths. I do realize this idea counts on a lot of things going in your favor; your opponent taking the bait, and getting the right roll for the side the flayed ones come in on. Alternatively, when outflanking if you can get your flayed ones in behind a transport, and wrap it, this can be a good way to take out the squad inside, as once the vehicle is wrapped, dump your heavy fire in to pop it. Boom, dead squad.
The other idea I had was using Imotekh's Bloodscarabs ability. It's obvious what this ability provides, but maybe not so obvious as what to do with them once they are in. This would be good to use against a unit of Long Fangs for example. Also the way the rule is written it indicates that any Flayed One squads looking to enter the game through deep strike will not scatter is deployed within 6 inches of the marked target. This means that you could bring in multiple squads using this ability. What better way to split the fire of your enemy than dropping up to 60 little buggers in their backyard without scatter or mishap? Again this could also be useful to wrap transports to focus fire.
Don't be afraid to use points to distract/misdirect your opponents. Be the Overlord, and sacrifice the insane Flayed Ones!