Main characters are playable characters who all play important roles in the lore of Sdorica.
All main characters are available at tier R, SR and SSR, with some characters start at N rarity.
Common characters are available through infusion. They start at N rarity and have high infusing rate.
Uncommon characters are available through infusion. They all start at R rarity and have average infusing rate.
Rare characters are available through infusion and Contract Crafting (for 20 Origin Stones). They typically appear at SR rarity and have very low infusing rate. In the Million Infuse they can also appear at R rarity.