Keyword: Amass

Amass 1. (Put a +1/+1 counter on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)
You and permanents you control gain hexproof until end of turn. (You and they can’t be the targets of spells or abilities your opponents control.)

When Eternal Skylord enters the battlefield, amass 2. (Put two +1/+1 counters on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)
Zombie tokens you control have flying.

Enter the God-Eternals deals 4 damage to target creature and you gain life equal to the damage dealt this way. Target player mills four cards. Amass 4. (Put four +1/+1 counters on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)

Creatures you control have menace.
−2: Amass 2. (Put two +1/+1 counters on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)

Up to one target creature gets -2/-2 until end of turn. Amass 2. (Put two +1/+1 counters on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)

When Vizier of the Scorpion enters the battlefield, amass 1. (Put a +1/+1 counter on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)
Zombie tokens you control have deathtouch.

At the beginning of your upkeep, you lose 1 life and amass 1. (Put a +1/+1 counter on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.

Flying
When Aven Eternal enters the battlefield, amass 1. (Put a +1/+1 counter on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)

When Lazotep Reaver enters the battlefield, amass 1. (Put a +1/+1 counter on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)

First strike
When Grim Initiate dies, amass 1. (Put a +1/+1 counter on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)

When Gleaming Overseer enters the battlefield, amass 1. (Put a +1/+1 counter on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)
Zombie tokens you control have hexproof and menace.

Counter target spell unless its controller pays .
Amass 2. (Put two +1/+1 counters on an Army you control. If you don’t control one, create a 0/0 black Zombie Army creature token first.)