The moment Cyborg lost contact, Darkseid knew. Everything Cyborg saw would be instantly uploaded to the network for backup.
Darkseid not only knew what Cyborg had gone to do, but also how he had died. At the same time, he learned that Deathstroke possessed shapeshifting abilities.
His first thought was whether the Highfather he had seen earlier had been Deathstroke in disguise, but he ultimately ruled it out.
That Highfather had been nearly identical to the one in his memories. Other than having newly acquired ten Power Rings, both his temperament and habits had matched the Highfather Darkseid remembered.
As for this Deathstroke, according to the intelligence currently available, he was a warrior and a user of Deviant energy. He was a complete stranger. Neither Darkseid nor Highfather had ever seen this Deathstroke, and likewise, Deathstroke could not possibly have seen either of them.
Without having met them, he could not have impersonated them.
Moreover, the powers displayed by the two sides were fundamentally from entirely different paths. Darkseid did not believe a lowly human could wield two energies with completely different attributes.
Deathstroke had once used ten Power Rings to defeat the alien sea beast known as the Flood Demon. But at the time, Darkseid, Cyborg, and the others had all been inside the Spectre Sector. Darkseid himself had lost all his power and had no technological equipment at hand, so he had no idea that it had been Deathstroke's power.
So he still decided it was more sensible to remain on Sepulk and confront Highfather from afar. After all, in a few hours, once the garbage from his universe had been cleared away, he would accelerate the Ark and take the entire universe out of the current Multiversal System and into a broader expanse.
Only he could accomplish