CLS event doesn't work

R2 is definitely a great unit so he's worth leveling up, but I understand being tight on resources. It's been so long since I did this event. I don't recall what levels my characters were at. It looks like you're meeting the requirements though, but to pass it, you're going to need R2 to be at least gear level 8. So, I think you should work on leveling and gearing up R2 to see if that works.