Szarekhan: Uncanny Artificers

The Szarekhan exhibit a deep-rooted ability to
fashion and maintain the finest wargear of any
Necron dynasty. Every blast and blade-stroke
the Szarekhan level at their enemies is lethal in
the extreme.
You can re-roll a single failed hit roll and a single
failed wound roll in each phase, as long as the
attack was made by a model from your kill team.