Both characters are similar, but they have different paths. Caelus is a version of the protagonist that is more someone who thinks before acting, cautious but strong-willed, a protector or strategist, someone shaped by responsibility or past burdens. Stelle is a version of the protagonist that is a risk-taker, someone who acts from instinct, hope, optimism, or emotional openness, a desire to break cycles or push forward. Even if they have the same features as hairstyle, same attire color design, etc. They have different motifs and personalities and that’s what makes them special.