Incorporeal Passage. The Undead Commander can move through other creatures and objects as if they were difficult terrain. If it ends its turn inside an objects, it is shunted to the nearest unoccupied space and takes 1d10 force damage for every 5 feet traveled.

Grim Harvest. When the Undead Commander reduces a creature to 0 hit points it regains hit points equal to your Wizard level. Any hit points gained over the Undead Commander's maximum hit points become temporary hit points.

Deathly Touch. Melee Weapon Attack: +4 plus PB to hit, reach 5 ft., one target. Hit: 1d6 plus PB cold damage.

Chill Touch. Ranged Spell Attack: (your spell attack) to hit, range 120 ft., one target. Hit: 1d8 necrotic damage and the target cannot regain hit points until the start of the Undead Commander's next turn.

Multiattack. The Undead Commander makes a number of Deathly Touch attacks equal to half your proficiency bonus (rounded down) or uses Chill Touch.

Command the Dead. The Undead Commander issues a mental command to any undead you control as long as they are within 120 feet of it - it will use this ability whenever it can in pursuance of the objective(s) you set to the best of it's ability.

It can command any or all of them at the same time, issuing the same command to each one. Once given an order, a creature continues to follow it until its task is complete.