Blason

Apparently you're not supposed to leave blason at 11, but I ignorantly maxed it early on. I was thinking about either taking some skill points from each Lune, Final feint, Mist to max Rapier, or I could simply leave Rapier at 11. Anyone got any better ideas?

Leave rapier at 11.

You are supposed to leave Blason at 11. And all the other skills besides it are much more important than rapier, leave rapier at 11

In 3rd job you are given 2 choices to leave at 11 or max.
These are Blason Fantome VS. Rapier Wit
Normally you are suppose to max Rapier Wit since it works alongside Penombre
Since you maxed Blason Fantome, don't feel discouraged. I rarely use Rapier Wit since Penombre's damage is so strong when spammed, I'd hate to waste some extra frames on Rapier Wit.
Leave Rapier Wit at 11.
If you are still not satisfied you can always wait or buy an SP reset scroll.

Maxed rapier is a good chain attack with Penombre(Twilight)