Beast Lord
The second strongest beast-summoning Reyvateil-type enemy, who is also stronger than both the Bird Lord and the Mech Lord.
Aside of pretty much exclusively summoning Mist Walkers, which are pretty dangerous enemies on their own, she can also sing Aurica's strongest healing song: Life Shower, pretty much undoing all of the damage that was inflicted on a single enemy. She can also attack all vanguards at once with her Earthen Horn skill, which delays the turns of everyone who got hit with it, and finally, she can summon a cerberus-like beast with her Lv. 3 Stored Attack, Hell Paradise Doggy, which deals a large amount of damage.
Unlike the other beast summoners, you'll have to fight quite a bit to defeat her and her minions, so don't hold anything back and use your best skills and Song Magic to have a chance.