Lautrec is a very no-nonsense Professor-- to the point that even his rank and position within a prestigious Magi Academy is of little concern to him, but rather a means to an end of teaching those who are willing to learn many incredible powers.

He can appear harsh, even a bit cruel (or extremely petty depending on how you view his attitude and 'punishments' for lacking results), but what this outward personality belays is his sincere intention to make people better for his instruction. And because of this dedication to his work of magic, he can be one-minded, ignoring his own needs, and other's needs, to see improvements in every aspect of magic power; he is also quite aware of how being sound in mind and body helps tune these mystical powers, but has worked so hard that he is able to forgo many of his own needs to push others further.
If it isn't obvious, he is very stubborn and rigid-- and due to his vast knowledge on a difficult subject, he treats many of even his peers like bumbling students that require his nit-picking corrections.

His life and his power is what he considers his own 'calling', and is content to have the amenities he is given by being a professor; even his hobbies rarely leave the 'branch' of magic studies, and will usually experiment with spells for fine-tuning or for entertainment. He has little worries about what others think of him, and is not vain whatsoever, whether its in his (unintentionally) self-made prestige or appearance.