This quest is called In Defiant Challenge and used to be a real tough one, but improvements to the game have made it some what easier. I have pasted a walk thru for the quest you need below. It's a pretty detailed walk thru, offering you either the key item method or the mob drop method. The mob drop method was the only method that was available when I did my 50 limit break with dinosaurs walked the Earth.
The second attachment is a link to ALL of the limit break quests, also known as Genkai, which mean limit break in Japanese. You will find that all of the walk thrus are pretty detailed, since every single player has had to do them, obsess over them, cry, sweat, swear, throw controllers.....well, you get the idea. Exoray Mold, that one was a controller thrower!!! Skyfiredancer (talk) 09:14, October 1, 2015 (UTC)