Gandalf’s speech to the Balrog

[Elrian]

I think one-on-one Feanor would have been a match for even Gothmog.

Feanor's skill was more in craft than fighting. With the Silmarils he may have defeated Gothmog, without them, very doubtful.

I do think Narya aided Gandalf in his endeavors,like reviving Theoden, but it's power wasn't used or could be used as a defense or against attack.