*This was the last achievement I got because it was so specific
This isn't entirely a solution, but I can almost guarantee your odds of finding Devil Kazuma is WAY higher in Arcade Mode vs. Treasure Battle.
I was on a 55-win-streak in Treasure Battle, found Devil Kazuma and got my butt kicked. Sad. haha
But then I played Arcade Mode, finished it and she was the final boss, and that was easy as cake. I'm not sure if the end boss is always the same, so that's why I mentioned this. Hope this helps!