Being a breed of sleipnir conditioned to be the perfect faithful war-horse. Uncannily skilled in warfare, able to sense the moment and flow of battle, and carry out maneuvers of some difficulty, such as the timely withdrawal from a fray to regroup and strike anew. The conditioning wrought on these creatures by the masters for whom they once fought was so steely that even after countless generations of breeding in the wild, it has faded not in the slightest. A tragedy indeed, for they consider all those not hailing from their long deserted homeland to be enemies, and attack on sight.
At precisely what point the polished destrier mane came to be used as a device for the casting of magicks is unclear. The noble steeds from whence such mane-coverings came were name by a sorcerer, however, and perhaps this association has given them their magickal properties. As tools for the casting of magicks go, these are among the best.
Mesmenir's name is a portmanteau of the word "Mesmerize", the act of Mesmerism, or using the animal magnetism, and the suffix of Sleipnir. The Mesmerize part of its name is a reference to the monster in Final Fantasy VIII, whose name it shares exactly in the Japanese version.