[BloodWitch]Ravnica at War #2

Dreadhorde Army:

Zombies of Amonkhet are eternalized creatures, known as Eternals, are the conclusion of those who pass the trials and are slain by Hazoret. They form Bolas' lethal undead fighting force, the Dreadhorde, that has transcended their mortal capabilities. They are embalmed in layers of lazotep, a valuable blue mineral, that preserves their lifeforce as well as deeds in life.

The Eternals are elite soldiers with all the skill and prowess of living soldiers, but none of the disadvantages that arise in living beings, such as emotions, hesitation, or disloyalty - and not being "living beings" lets them be deployed across planes, given a means of transportation like the Planar Bridge. Bolas has personally crafted all of Amonkhet to create just such an army.

God-Eternals:

As Oketra was slain, mummies began to embalm her corpse. The purpose of this was revealed in War of the Spark, where the Dreadhorde was joined by the monstrous abominations that were once the Gods. They are coated in massive quantities of lazotep, allowing them to enter Ravnica and cause chaos there.

The Lazotep Plating:

Lazotep is a magical blue mineral exclusively found on the world of Amonkhet, which interacts with necromancy in strange and powerful ways. It was the main reason Bolas turned his attention to Amonkhet.

Originally, the people of Amonkhet used Lazotep to seal the wandering dead in tombs. The mineral was mined extensively in the Broken Lands by servant mummies, and used in the creation of cartouches, indicating its role in control magic and the preservation of life force and a person's deeds in life. Ultimately, lazotep was also sneaked out in the funerary barges of the worthy dead, where it was used in the Necropolis to create Nicol Bolas' eternal army, resilient undead coated with layers of the material. He then transferred this Dreadhorde to Ravnica by way of the Planar Bridge which could only transport non-living matter.

In my game, the Lazotep plating was set as an anti-magic shield. the Lazotep will deflect all spells that require a target to cast. For God-Eternals, they will gain Limited Magic Immunity:  Which makes them not affected or detected by spells of 6th level or lower unless they wish to be. They also gain advantage on saving throws against all other spells and magical effects. You can adjust this ability based on the level of your player's team.

Other variations of this map: