You’ll want to pick the monster who you want to level up from your monster box on this screen. To get to the Power-Up Fusion screen, tap the “Monster” icon, and then “Power-Up Fusion.” This will take you to the “Select Base Monster” screen. I’ve prepared this Power-Up Fusion guide to help you understand the variables at play, and to start you down the path of maximizing your monster’s levels. While Power-Up Fusion is key to building up your power, it can also be quite complex for a new player. They earn experience via Power-Up Fusion. They don’t earn experience in combat, though. In order for your monsters to gain levels, and therefore power, you must give them experience. Posted June 30, 2013, Updated April 13, 2014, Power-Up Fusion | Puzzle and Dragons