nobody ever talks about the part of Damian's story that shows he's the youngest child
after all the hardships and the struggles and the learning curves and everything, after the battles are won and the losses counted and everyone goes home and rests and life gets to be as Normal as it can be for them
They will leave him and everything that they taught him about Friendship and Loyalty and Family and Always Being There For Him is gone. Because they're gone.
Even Duke, the closest to him, is older. He will leave. He will move out and find his own apartment, his own life, his own inside jokes with people who aren't Damian and Damian will be stuck. At home. Alone.
Sure, his siblings are (for the most part) close by. But they don't live there. He cannot just cross the hall and ask to hang out. He needs to text them. Make plans. Ask them to schedule time in their days for him. Since when did they need an event to see each other??
Outside of all of the masks and capes and Events and shit
Damian is still the youngest child. And as such, inherently, he will be the one left behind.