>>17
You can refine 100 from Laguna Card I think, but if you're short on them, you can also try a trick, but it'll require some luck. Less reliable but free... Equip Rinoa with Initiative and get her to limit. You could also add Auto-Haste just in case. Then right when battle starts launch a Limit Break and pray for Invincible Moon.

Oh, and you can also refine 10 trials into a pure one.