This level is really straight forward, and you don't need to prepare for it. Just go through, and every time you see a new enemy with a power, inhale it. The next room will be blocks with the power you just took, guarding a feather. Then you'll fight mini-bosses, who you will also have to take their power, to get the feather in the next room. Repeat this about 6 times, then you can really make the Angel happy by giving her all her feathers for her wings back.