How to obtain
Before the Grass Temple
Go to the left house of the two at the very top of Raejack and tell him to choose his childhood friend over the rich dancer by the name of Mary
After the Grass Temple
- Travel to Ortego in Sector E3 and speak with the old woman located near or at the front gate
- Travel back to Raejack and go to the same house as above to find Mary outside the house. Speak with her
After getting the Light Orb
- Go to the top right corner of Ortego and speak with the random guy to get Autograph Paper
- Go and talk to Mary, in the same village, to get Mary's Autograph
- Go back and again talk to the same guy in step 1 to get the Giga Sword