At the end of the day, the actions and intentions of a person could be interpreted completely differently than those intended by another person.
If enough beings misinterpreted someone's intentions, they turned into the truth. That was just how the Universe worked.
Many misinterpretations were wrong, and they turned a person with good intentions into a villain, who wanted nothing but the worst from the Universe.
That was how Damian turned into the biggest Villain known in the annals of history, even though his intention had been noble.
He was a murderer, who desired to rule over the universe. That was it.
Not even the fact that he voluntarily retreated once he killed his targets was interpreted in the correct way.
Everyone just assumed that Damian had been injured by the Spectran and that he retreated in order to recuperate. But listening to Nial caused many questions to surface in his mind.