Derrick is the older brother, vinter is the white haired guy, and callisto is the prince.
Derrick --> oldest brother
Callisto --> crown prince (ml)
Vinter --> sorcerer and leader of the information guild
Derrick is Penelope's eldest brother (the dark haired one). Vinter is a Marquis who is also secretly a powerful sorcerer; he is also one of Penelope's love targets in the game. Callisto is the crown prince who's notorious for being cutthroat; he's violent but he's a good leader, especially in the war.
Can you please help me recall? Who the heck is Derrick, Vinter and Callisto? I’m really sorry but I don’t remember annoying and rude shits like I only know Penelope...