A little pain went a long way.
Katja Kankaanpaa, Invicta FC's women's strawweight champion, has one of the most unique nicknames in all of MMA: "Killer Bunny." The story of how she got it starts with a bunny she used to own as a pet named Alice.
"One time, she attached to my husband's ankle," Kankaanpaa told MMAFighting.com "I think 'Killer Bunny' is a very good nickname since that day. Because bunnies, when they fight, they fight hard and they don't give up."
The Finnish star has adopted the nickname and also that mindset. Kankaanpaa bounced back from a 2013 loss to Joanne Calderwood to win the Invicta 115-pound title against Stephanie Eggink last October. She took a beating early in that fight, only to rally and submit Eggink in the fifth round. It was one of the best in-fight comebacks of the year.
"I just want to win the fight," Kankaanpaa. "I think one goal was to win the championship belt last year. Now, my goal is to defend the title. There are other girls, they want the title. It keeps me very motivated."
There's little doubt that 115 pounds is the best weight class in women's MMA. Eleven Invicta fighters from the division were acquired by the UFC in 2013, yet there are several very talented fighters remaining, beginning with Kankaanpaa (10-1-1). She owns wins over current UFC competitors Aisling Daly and Juliana Lima. Her lone career loss was against Calderwood by unanimous decision.
Kankaanpaa, 33, isn't looking to jump ship to the UFC, either. She has work to do, beginning with Souza on Friday. Then there are women like Alexa Grasso, Karolina Kowalkiewicz and Mizuki Inoue on her agenda.
"I'm very happy where I am now," Kankaanpaa said. "Invicta treats me well. They offer me tough opponent and fights, so I'm very happy where I am. I don't know what the future brings."
Many believe Grasso would be a clear future challenger, especially after her impressive victory over Inoue at Invicta FC 11, a performance that caught the eye of UFC president Dana White, who was in attendance at the event. Grasso has rapidly become not only one of the best women's MMA prospects in the world, but also one of Invicta's most well-known fighters.
"If Invicta wants me to fight with her, that's OK with me," Kankaanpaa said. "She's very young and talented. She's very good, but I'm better."
There is confidence in Kankaanpaa's voice. She has prepared very hard for Souza, who she suspects will attempt to take her down and use her superlative Brazilian jiu-jitsu based on watching her old fights. That's fine with "Killer Bunny." She, too, has experience on the ground and actually finished Eggink at Invicta 8 with a fifth-round D'arce choke.
"I'm prepared for all situations," Kankaanpaa said. "I have my own game plan. Let's see what happens."
Best-case scenario? A finish for the Finn, of course. But that isn't necessarily what she has trained for.
"Whatever it takes, but I think a TKO would be nice," Kankaanpaa said. "I don't know -- third round. But my cardio is very good. I could fight five rounds if I had to."
Or more. Just like in Kankaanpaa's spirit animal, there doesn't seem to be much quit in her.