Magician Reyvateil
Like their more physical-oriented counterparts, the Battle Reyvateils, these Reyvateils are a large step-up from the ones encountered previously due to the experiments that were performed on them to strengthen their Song Magic. This is reflected on their high stats and completely magic-based skill set.
Their skills are Limit Break, in which they surrender to their emotions in order to blast the party three times with energy, and Major Song, which launches a series of energy balls to the party. Both attacks need precise timing to be blocked perfectly due to each hit coming right after the previous one, so the player needs to be very careful while fighting them. Thankfully, they have a relatively low HP, so it should be possible to defeat them before they have a chance to attack.