Well, it depends on how you want to describe it.
Do you want to describe it as emotional resonance in the empath, or would you prefer to talk about it as the other character's emotional state?
Do you want to detail how these external emotions are affecting your character, or what they learn from feeling them?
It also depends on how strong the emotional resonance is. Does the character get actual symptoms from these emotions, or are they just aware of them on an abstract level? "Oh, that girl is happy!"
Are you writing in first or third person?
Well, the main thing, is whether you want in-between words. It's just like the other five sense: 1. "Michela/I watched the agonized knight as he writhed through one muscle-tearing contortion after another." or 2. "The knight writhed through one muscle-tearing contortion after another."
It's the same in first or third, how many layers of perspective do you want to strain this emotion through? If you use both the MC and the text as filters, you're going to have to do a lot of literary acrobatics to avoid "felt" constructions, but if you use the second method, you shouldn't have an issue. "Michela felt the anger roar through the man's veins, tearing away at any sense of understanding or compassion." or "The anger roared through the man's veins, tearing away at ans sense of understanding or compassion."
If you want to have her experience strong resonance, you just replace "the man's" with "her".