Word on that. Especially since all we ever saw of him was his being annoying and disrespectful. And wasn't he trying to kill Alfred at some point? And they praise him and make him Robin? How does this all fit together?
And while the term "Mary-Suism" is sorely overused, Damien fits the bill in too many ways: surprise!kid of the main character, mad fighting skills, now apparently mad mechanics skills as well, and can get away with all kinds of shit and is even lauded for it, ridiculously by exactly those at whose expense his actions go, and is promoted to the second most important position available virtually out of nowhere. Such utter bullshit.