So, I was looking through 8kun looking for how to visit Gensokyo to find out which touhou I could become, and found the super session stuff which I had forgotten about, I never did it because Snail said he had done it for me somehow and I just needed to do one to push through to the last level, is that true or should I do the super session?

Also is it necessary to visit Gensokyo in a group session to find out which Touhou I could become or is there another way?