Battle Fucker in Ilias Port University 3F.
In order to access the university's third floor, you must have done the Elficilin side quest. A quick summary: complete the second Tartarus, go to Enrika, talk to Micaela's door guard after speaking to the elf inside, talk to the dark elf in the item shop, fetch and return Healing shell from Lemuse Beach, then bring the Elficilin she rewards you with to the Doctor on the second floor of the university.
Fizz does 301 damage, she gives Diploma upon victory and becomes available for recruitment as a companion.
Fizz: "I'm busy writing a paper right now..."
"My thesis will be delayed because I am on a journey to save the world... there."
Fizz wrote a letter.
Fizz seems to have lost her glasses...
Fizz has become blind!
Fizz trips over nothing!
Fiz takes damage!
"I must finish this by tomorrow morning..."
Fizz is writing a paper.
"If I don't finish this experiment now... Ahhh!"
Fizz causes a gigantic explosion! Allies and Enemies take damage!