Apparently you can also get repeatable CSCs by:
winning using five or more skills (UC1),
"Inversion victory from the situation of the LP difference between more than 3 times" whatever that means (UC1),
And, winning without any damage. (Standard 2)

blade_anime wrote:"Inversion victory from the situation of the LP difference between more than 3 times" whatever that means (UC1),

That's defeating your opponent when she has 3 times or more LP than your Shinki currently does. So if your Shinki is down to 100 LP, you'll get the achievement for beating an opponent on your next turn with the opponent having 300 or more LP.

Some question about the CSC, I had just recently bought a Arnval Mk.2 and Sharatang(Violin) but don't know which CSC is the best for them.

I'm now thinking of getting the rare CSC which are the Moonstone, Cat's eye, Black opal...etc for them is it fine with that?