Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Ghostly pact. when in combat it can summon 4 ghostly swords. The weapons are considered magical to overcome immunities. The swords do force damage

Multi attack. Makes two melee attacks.

Sword strike. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit:  5 (1d10 + 1) slash damage 5 (1d10) force damage

Sword parley. if struck by a melee attack it uses its reaction to half the damage unless caused by radiant damage.