[ Joe's seen her request to read the text aloud, so he's opting for a video. To make it clear that she'll need her telepathic ear plugs, he holds his own up to the omnicom's camera for a few seconds and then tucks one into his ear with very blatant movements. He taps on it for good measure and points at her.

After waiting ten seconds, he begins to sign. ]

Hi, Batman.

[ He looks a little dubious, but he's had the interdimensional future concept explained. She could be Batman where she's from. Tiny Batman. ]

I don't know where the training room exactly, but you should let me know when you find it. I've always wanted to spar with Batman.

[ It's very hard to work in words like Robin and Nightwing casually, but he's curious where they would fit in with her. ]

I'm used to him being broader.