For those who have never seen these cards before, there's an explanation of these cards from Wizards of the Coast published back in 2005
It can punish decks that run cheap spells, or that aim to cast multiple ones during a single turn
Ghost Ark Coming from the grim darkness of the far future, Ghost Ark is a way to get a bunch of utility from artifacts in your graveyard, which is perfect for a Necron-themed deck
Both of these cards are already extremely powerful in artifacts-matters decks, making this combo a shoo-in for the archetype
In the game, this is obtained by a number of different versions of the OmniDroid that can be played on previous version in order using shift
You get pseudo-card advantage, which can allow you to cast spells that target your Vehicles, and it also gives out +1/+1 counters for each spell you cast during your turn