Mordru

Before Injustice 3
Mordru is one of the Lords of Order, also known as Council of Eternity, he and the other Lords are sitting in Rock of Eternity's Throne Room. During Injustice 2, the Council concludes that as long as Batman's and Superman's war continues, there can never be order. The Council manipulates Doctor Fate into aiding Brainiac, as they believe that he can impose Order. When Aquaman and Black Adam fight Blue Beetle and Gorilla Grodd, they watch the battle, but remain hidden from them. After Superman destroys Helmet of Fate, Mordru looses faith in Brainiac stopping the war and insists that they must choose a side in Finest Duo's conflict. As the rest of the Council disagrees with him, he proceeds to kill them and absorb their power. When he kills Wizard and Amon-Ra, Black Adam is weakened, which allows Batman to defeat him. Before Batman's and Superman's final battle, Mordru managed to kill all the other Lords, absorbs their powers and uses them to split the timeline to one where Superman won the whole war, and the other, where Batman won the whole war.

Injustice 3
On Superman's Earth Black Adam suffers from the lack of Amon-Ra's powers, so the Regime decides to go to Apokolips and grant him Darkseid's power. When Black Adam fights Darkseid, the latter easily defeats him, and impales him with Black Diamond. As it turns out, the result of this action is that Black Adam gets Eclipso's powers and defeats the Lord of Apokolips. He then returns to Earth and through connection with Eclipso, learns of Mordru's actions, and travels to the Rock of Eternity and fights him.

On Batman's Earth Atrocitus attacks the Circle of Trust and kills Green Lantern. To prevent the ring from seeking new canditate, he sends Jordan's body through Boom Tube. It turns out he sent Hal's body to Void, where Spectre, Trigon and Mr. Mxyzptlk are constantly fighting. Spectre takes posession of Green Lantern's body, and defeats the other two. He then tracks the power which transported him there, and ends up on Rock of Eternity, where he fights Mordru.

After Black Adam/Eclipso and Green Lantern/Spectre defeat the Lord at the same time, and the heroes merge two timelines, Eclipso reveals that he wants to rule the whole universe, and Green Lantern/Spectre has to fight him. After the fight Spectre reaches with his hand with the Green Lantern Ring, to Black Adam's heart, and removes the Black Diamond. After the Black Diamond merges with the Green Lantern's Ring into Black Lantern Ring, and flies away, Spectre says that he can't help the heroes anymore, as he has to stay on the Rock of Eternity, to guard Mordru, and to maintain the Rock of Eternity's stability.