Necrons: Abyssal Staff?

[Saturn 3]

Can someone please explain how I wound with this? It says it goes against leadership but I dont understand how this goes down.

[Rev. Tiberius Jackhammer]

You treat the enemy's Leadership as though it were its Toughness. If you're firing the Abyssal Staff against a Ld7 guardsman, you treat it as T7 against the Abyssal Staff's attack.

[Encarmine]

which means you would wound on 3s vs guardsmen

[Saturn 3]

Thank you very much.