Finding Ego Orb
Search in the lost underworld near the fire spring. You may have to do a lot of walking to locate him.
Finding the Broken Antenna
It is located in Tenda village in the junk yard.
Infinite Magic Butterflies
Go to the cave in Onett and find the location where you can see the giant step but cannot get to it. Keep entering and exiting this location, heal yourself, then get more butterflies as needed.