(Spoiler Warning in affect if you haven't finished the fate stay arc"s until fate Apocrypha of the anime then don't read any further then this. You have been warned)

Honestly as far as I have went with the show I can tell that Mordred wouldn't be happy for a few reasons, the main one being confronting Arturia after hundreds of years of being apart.

The second reason would have been more out of disappointment then resentment for not facing Arturia in her original form, state as well as discovering she has fallen from grace both figuratively and literally.

I have tried to search the farthest reaches of the internet for this same question as well as using different wording with very little luck.

So here I am, and as such with all the knowledge you guys have of the series that include the strengths weaknesses and abilities of both Arturia (Fallen) and Mordred who would win in such a battle as well as the previously mentioned question.