In the works:
Instead of deploying Ghost Arks that are capable of repairing necron warriors mid-field, Harut discovered it was much more efficient to phase damaged units back to the closest tombworld for repairs while, at the same time, maintaining an open portal between these endless vault-crypts and the battlefield.
These hovering portals bring forth an endless stream of deadly Necron infantry, pouring forth Gauss flayer fire in a constant barrage of death.
I really wanted mine to be actual swarms!
The Dakhma Dynasty deploys these instead of monoliths, a single colossal squid-like warmachine that drops from orbit and burrows inside of the earth itself.
Canoptek Tentilla: Doomsday Cannon
counts as Doomsday Ark
One of the tentilla appendages ends up in massive doomsday cannons. Burrowing and emerging from the ground from angles that make any formation by the enemy easily countered by simple redeploying heavy weapons from a different angle.
Canoptek Tentilla: Tesla Destructor
counts as Annihilation Barge