This is a major problem. I'm pretty sure I need Li in order to properly finish the game.
So I reach the veil and I have all the forms except for light. I decide to have some fun and try to scale the left side of the sun temple using beast form. I quickly realize I can get good progress in plant form by using the sprout things for grip. I launch one straight at my feet and rocket upwards... right into the broken window that goes to the boss room in the sun temple. I figure this isn't too bad and beat the boss in one try. I then head backwards through the cave to the normal chambers of the sun temple and make my way up to the lost memory where a young Li is featured on a boat. Now I decide to go and find Li, but once I reach Li's cave, he's not even there! What do I do?
EDIT: Li is found, all is well, but doing that plant thing rockets me upwards. Pretty cool.
