Council of Elrond

Hello:

If two companies move to the same site in one turn, can the opponent play at the site one on guard card for each company that moved, and so the site ends with two on guard cards at the end of the m/h phase?

Thank you.

Yes, you will end up with two on-guard cards at the given site.

Thank you. I suppose then, that I could reveal both of them, for example modifying the aa with the first, and giving a creature with the second, or something else.

Yes, that is possible.