So I'm trying to come up with an exact explanation for the interaction between non-necron Deep Strike units and the enslavement dial. Note that I'm assuming that the designer's intent is that Necrons can't simply bypass the enslavement dial by deploying units into reserve. If I'm wrong, disregard the following rambling.
The Legions of Death rules insert says (paraphrasing, as I don't have the English insert at hand):
The Necron player can deploy or put into play, aside from Necron and neutral cards, only cards from a faction that matches his enslaved faction.
The recently spoiled rules insert from the Jungles of Nectavus says:
Each round, during the deploy phase, a player has the option of using a deployment turn to deploy a card with the Deep Strike keyword to a planet facedown for 1 [Resource] instead of deploying that card normally for it's regular cost. (...) Being in reserve is a game state that means the card is in play but facedown. Cards in reserve do not have any characteristics, including title, cost, text, card type and traits. (...) Units that a player Deep Strikes are in play at the planet where they were in reserve (the unit is not considered to be entering play).
So, to get the obvious out of the way: deep striking a unit gets around the enslavement dial, as it's not considered to be entering play, so the limitation doesn't apply. But what about deploying it into reserve?
Does a card still posess it's characteristics (faction included) when the player announces his intent to deploy the card? Presumably so, as this is what allows us to use various card discounters in the first place. If so, I understand that the enslavement dial being set to a different faction would make the player unable to initiate the deployment process at all.
Now, if the above is true, let's jump to a non-Necron related question: can we discount the 1 resource cost of deploying a card into reserve using any discounters that apply to the card characteristics while it's still in hand? To give an example:
Can we discount the 1 resource cost when deploying Valkyris Pattern Jump Pack (attachment) into reserve, while having an Ambush Platform (discount 1 when deploying attachments) in play?
This would obviously tip off our opponent as to what we're deploying, but is it technically possible?