photon crystals

[adonis565]

Max Attack! Max Attack! Any route on normal or hard, you'll find plenty.

which maximum attack there is 4 of them

["En"]

Max Attack 4A or 4B (Episode IV, of course) would be ideal. All rare enemies in Ep.IV Normal drop Photon Crystals, and those two routes contain a high amount of Sand Rappies and Merissa AAs. 4B also contains many Zu's, but they may just slow you down if you're not using a Force with Ra-type spells.