Levi will provide a military-styled report about his and Eren's latest expedition, detailing Margaret's testimony about the seven mysterious people who came from other worlds (Doctor, Scientist, Wizard, Knight, Pierrot, Icarus, Heracles) and everything else she mentioned. (He will also share this information with Olwen, or let Helene do it, or perhaps invite him over for the report, whichever works best but I'm not reposting this on his toplevel too since it's pretty much the same thing -- if he'd have a unique reaction feel free to threadjack with him. :').)

They will also deliver some "Moon Ore" that they were able to retrieve and mention there is more that could be extracted with the appropriate tools.

Finally, he will request a teleport crystal that he could deliver to this location as per Margaret's wishes (and they could dig some more ore while at it if needed).