I can't believe I just noticed this, and maybe someone else has noted this already. But Damien has a habit of wringing his hands around his cane when he's stressed.
Dark does something similar: he pulls at his lapels when he's stressed/pissed/scared. You see this a lot in "Darkiplier vs Antisepticeye" when things start to unravel and even at the very end with Dark!Chica (although it's cut off at the bottom).
Always the hands in fists, always the tension over a lack of control over the situation. Perhaps Dark does this because he doesn't have anything to fidget with anymore.
This man has been so goddamn stressed for over a century, let him REST.
Something I’m pretty sure I’ve said before but no one else talks about is in Darkiplier vs Antisepticeye Dark just goes so hard on Anti for no reason and Anti has zero reaction to it
Dark basically says “why don’t you go kill yourself again?” and Anti’s response is basically “why don’t you go put on more makeup”
Dark my man I love you but you did not need to go that far and Anti what the fuck was that response