Damian Wayne revealed!

His Voice

Damian was most similar to Cass, be it the way they moved silently, almost soundleessly and without detection, their dark hair and past of killing within the league of Assassins or the fact that they rarely ever spoke.

Cass would let her actions speak for herself most often and understood the others mostly by their body language, which was her first language, but she'd occasionally express what she thought in words. Most of her words were either a warning or held with love for only her dearest and most important people to hear. As with body language, they held only truth.

Damian, on the other hand, was a naturally quiet speaker.

He was almost mute, voluntarily so as Talia affirmed and a later scan had shown there to be no issues with his vocals. He was most vocal during patrol unless someone else could speak for him; he talked via sign language like Cass. Sure, he'd threaten them so much his hand gestures sometimes turned erratic with the threat he'd promise them until they were indecipherable.
No matter how often they asked him the reason for his silence he'd shake his head at them and frown, signing 'privacy' or 'none of your buisness' or the like. Eventually, they assumed it was because his silence was its own kind of rebellion for him, be it because he didn't want to stay with them or didn't trust them. Or the league traumatised him so much he didn't have any words left to use for himself.

If only the reason was that simple.

Damian's silence was due to his heritage, but not because he was, as they called it, 'a traumatised child'.

No, it was due to his bloodline, something Talia hadn't mentioned to them on purpose.
The Al Ghuls were the possibly oldest bloodline to date back, Ra's al Ghul having been alive for nearly hundreds of years and stemming from a much older era.
The numerous riches of the league mirrored the eras he's lived through as much as the civilizations he's conquered and erased. So, with all the artifacts and the effects of the Lazarus pit, it wasn't that much of a stretch to assume magic or witchcraft was something resident to the halls of the Al-Ghul compound and within their very blood.

Ra's, Talia and Damian had an ability. The ability to command, the ability to misguide and the ability to realise.

Ra's was the foremost ability:
The ability to command.
It enabled him to make anyone obey him, even against their will.
It subdued the strong-willed and conquered the weak. No one could refute him, making his empire stay strong for centuries against any natural and unnatural forces. His ability only had one weakness: it's form. He needed to choose his words wisely, consider its many meanings as they could open loopholes to his commands.
Take for example the order to 'deal with it': it could infer that they should kill a person or imprison, punish them or even rescue a person - deal with them to how they wish. Hence his words are like chains or rope around the limbs or throat, possibly chocking you or giving you the opportunity to cut through the lock like a needle.

His daughter, Damian's mother, Talia, had a similar ability to her father. She could use her entire body language to misguide.
It was an illusionairy power that could even allow her to escape her father. She could send an illusion of herself - or even her shadow- and make it pose, act and speak as her. Though if a direct hit was emposed, striking through it, the shadow would dissolve into dark mist. Her's was deception in every form of illusion and thus something Damian, her son, learned to distinguish by the time he could walk. Lies were as inefficient as empty promises to him. He could walk into an empty room and be able to tell his mother was walking right next to him, her presence and form disguised entirely by her power.

Damian fell for no tricks, but he could also make others fall for his words. His ability could make his grandfather's and mothers power surrender with a single word.
His power, the ability to realise, [Realisation], allowed anything he said to be evoked.
Like a summons for the monster under his bed, that he'd 'killed his opponent' even if he had not done anything but breathe - all those statements would turn into the truth if he just spoke them. Damian's word was both truth and law; he could make truth into falsehood and falsehood into truth. He could bend reality like a God if he so desired.