Alvin Vest isn't exactly a mean person, but he's not great at being kind. He speaks matter-of-factly and doesn't pull his punches. He is exceedingly intelligent, his specialty being mathematics and science. His discoveries in physics and statistics have advanced the progression of science more than anyone would expect from a high schooler.

One of the three rivals, Alvin, is analytical and calculating. He doesn't like things deviating from his usual plans and will get upset if things go awry. His relationship with his twin sister is one of comfort, not that he comforts her or vice versa, but she is comfortably predictable. She protects him and occasionally calls him a massive nerd, but it's always the same. That predicability being disrupted by Eddie's appearance in the Adora route of the game is what causes tension between Alvin and Eddie.

Alvin has a lower, masculine-pitched voice and speaks in a monotone and unfeeling way. Similar voice claims for Alvin are Ryoma Hoshi from Danganronpa V3: Killing Harmony and Asmodeus from Helluva Boss.