Helms are classified based on their rarity: Common, Rare, Epic, and Legendary. The higher the rarity, the better the helm (they have higher upgrade value, better shadow abilities and more perks can be attached to them). Common helms do not have Shadow Ability and slot. All rare helms of a faction share the same Shadow abilities and they carry one slot. Epic and Legendary helms come with unique Shadow ability and they carry two slots.
Helms can be bought from the store. Otherwise, they can be obtained from chests won in duels, booster packs, or looted from defeated opponents. If the players receive a helm that already owned, a part of an upgrade bar will fill up. When the upgrade bar fully filled up, the helm will be upgraded, and a number of Shadow Energy will be given. Better chests and booster packs may contain helms with higher rarity. As for the drops from opponents, the players may obtain helms with random rarity; it is possible to get a helm with Epic or Legendary rarity, but the chance is small.
Some helms belong to some equipment sets, which gives a fight bonus when fully equipped. When the player collects a certain set for the first time, they can get a reward. The reward for each set only can be obtained once.
Special helms are limited-time helms that can only be obtained from marathon. They are only available during special events. Once obtained, special helms will stay with the players even if the event is already over. Their rarity are classified as Unique and comes with 2 slots.