Evandrus has short, chestnut brown hair, usually styled in a messy mop. He has a fair complexion. His hazel eyes tend to be broody, observing people under a half-lidded stare. His overall fashion is reminiscent of chaotic academia—a crumpled necktie over here, a mismatched pair of socks over there. His overall build can be described as somewhat lean.

Evandrus seems quiet—until he speaks, a tinge of bluntness to his words. Though he may come off as insensitive, he can be approachable enough—willing to engage in a teasing banter, cracking a smug smile. He tends to be disorganized, but somehow knows where things should be. It's rare to catch him nervous, but when he is, he starts sweating in buckets, and so he carries a handkerchief around. He dislikes overly friendly people, only because he doesn't trust them at first impression (a certified cynic), but there can be exceptions. His hobbies include playing Wizard's Chess and (secretly) doing embroidery. He has an interest in parkour, and would like to be more agile on his feet. He can somewhat speak French, but is not much fluent.

Evandrus was born in Exeter, England—an only child to Mr. and Mrs. Droit, a Muggle-born wizard and a wizard-born witch, who were well off (having invested in stocks) and travelled for business. He briefly spent his early childhood in Toronto, Canada, before returning to Exeter at seven years old. Having been exposed to his parents' magic, he was made aware about the existence of the wizarding world for as early as he could remember. As such, he was tutored at home. Despite spending most of his time behind closed doors, he didn't struggle at befriending like-minded people—even taking part of an underground Wizard's Chess Club at the local library (unbeknown to his parents). He became determined to be unreachable from his parents' influence.

Evandrus' first instance of accidental, wandless magic happened when he had just returned to Exeter. He was experiencing a nightmare on the first night, awakened by a deafening noise of his things—books on shelves, pencils on desk, toys in cabinet—each crashing down on the floor. This only heightened his fear, making it worse. Luckily, his parents were there to calm him down.