[oh so not even a friend of kaeya's. just someone's who's spoken to him - and knowing kaeya's tendencies to do anything for information, there's a high probability that this man is up to no good. a goddamn hooligan. because that's just the kind of person kaeya likes to 'just speak' with.

and archons, he's seen kaeya's 'memories?' which isn't diluc can totally wrap his head around, but if this place can just throw up people's private memories for anyone to see... well, it's an uncomfortable amount of invasion of privacy. and if it's kaeya's memories on display here, then it means there's a high chance diluc was in them.]

So you didn't approach me randomly. You recognized me from his memory, yes? What are your intentions. If you've done anything to hurt him-

[the threat hangs heavy, despite the fact that eustace has not really done much to imply that he's hostile toward diluc nor kaeya. but the possibility is there!!! and diluc is on guard!!!]