1. About Sidian

Cards can be obtained by defeating the enemy 'Irregular' that appears during class and exploration. These cards are the base unit of Sid Eternal called 'Sidian(s)', and players can collect more than 1,000 Sidians. There are five rarities of Sidian, from 1★(normal) to 5★(S.Rare), and level of card can be upgraded by fusing Sidian of the same card. Also, level of Sidian skill can be upgraded by using materials.