Oh, that's the Doozy of a mine I found and can't beat. I thought that was the one you were talking about when you said you found a doozy of a mime!I didn't know there was a Mime fight in the prologue
though, I did hear/see something about a bald mine fight that's supposed to be hard...I guess I could look into that fight
To make matters worse, the bald mime fight only allows you to select one of your characters to battle it. You also better have your parry and/or dodge game ready to go, because if the mime lands a single hit, it's a one hit kill unless you have more than 10,000 hit points or a shield. And even if you survive that hit, it throws you off from being able to block the rest in the sequence.
Look for a purple and blue colored portal on the mountain ridge just south of where you battled the Axions or west of Eternal Night. The mime is hidden in a portrait you have to interact with.