E-Sumi-Yan is a Padjal non-playable character from Final Fantasy XIV, and is the master of the Conjurer's Guild in the Stillglade Fane of Gridania. He plays a substantial role in the Conjurer class quest-line, and makes cameo appearances elsewhere.
Master E-Sumi is a Padjal, and thus does not appear to age past a certain point; his outward appearance remains that of a boy on the cusp of adolescence. His padjali horns take the appearance of a pair of tiny, black bull's horns. In Legacy 1.0 he wore a white-and black tunic with breeches and boots. In A Realm Reborn, he wears a floor-length dark gray-and-black robe, and his facial features have been adjusted to smooth his cheeks and bring more focus on his silvery eyes.
E-Sumi-Yan is nothing like the child he appears to be; while his exact age is not stated, he has been Master Conjurer and Hearer for decades. His calm demeanor and deep wisdom reflect this, and he enjoys training new conjurers and illuminating the mysteries of the art for them. The only time he grows cross is when dealing with Sylphie. This stems primarily from his concern for her welfare, concerning the dangerous form of conjury she uses.
Reintroduced during the adventurer's initial Conjurer quest, E-Sumi aids the novice in the fundamentals of conjury by sending them to learn about the elements alongside his troublesome and inexperienced apprentice Sylphie.
When Sylphie approaches E-Sumi to tell him she learned Raise, despite his fears of her lack of fully understanding conjury, E-Sumi unintentionally drives her away by forbidding her from casting it. E-Sumi and the other Stillglade Fane conjurers arrive too late to prevent Sylphie to from using Raise to revive a Wood Wailer she was treating. Though she endures, E-Sumi ends up hurting Sylphie's feelings.
E-Sumi later explains that her healing magic draws on her own life force in lieu of an understanding of the natural world that would allow her to call on the greater spirit of life to aid her; casting in this way will kill her. This is why E-Sumi finds it so difficult to deal with Sylphie, as her mother did perish because E-Sumi did not do enough to stop her from using her art, and he cannot bear to watch Sylphie fall to the same fate. This tests his usual objectivity and calmness, and he asks for the adventurer's further aid going forward.
E-Sumi-Yan also appears in the quest "Fear and Odin in the Shroud," where he reveals a startling fact about the blade Zantetsuken that sheds light on the nature of the primal.