There is a very famous passage in the Aeneid that narrates its hero looking at some pictures of the Trojan War, which he barely escaped from:
Miratur. Videt Iliacas ex ordine pugnas,
Bellaque iam fama totum vulgata per orbem,
Atridas Priamumque et saeuum ambobus Achillem.
This passage is almost completely straightforward, but I am a little bit uncertain about the use of ambobus above. Since it is an (numeral) adjective, I've searched for some ablative name that would be attached to it, but unsuccessfully. Could anyone figure out what the numeral is doing in this passage?