Demon's Tier+

Characters are unlocked in the tavern for a D-token; to get the trophy you need to unlock five characters, because the sixth, a knight, is available initially. If my memory serves me correctly, all characters need around 195,000 D-token. I recommend opening them in the following order: first open Archer, then use it to immediately accumulate coins to open Assassin. And then they can complete the game and earn coins to unlock other characters.