Hero in the Call to Arms set.
hero. Rylai, the Crystal Maiden is a well-known Spellcaster. She has a natural ability in frost magic and was banished to the cold northern realm of Icewrack by her own parents after her abilities turned out to be causing too much trouble. There, she was taken in by an Ice Wizard as a pupil. After she completed her study, her control over magic of ice and frost became unparalleled. While not the most skillful fighter, her magic gives her great utility on the battlefield, freezing and slowing enemies while providing a useful Arcane Aura.
In Dota 2, Crystal Maiden is a popular support hero, requiring little gold to be effective on the field. Her Crystal Nova deals damage and slows enemies in an AoE, Frostbite allows her to freeze an enemy in place, Arcane Aura provides global mana regeneration, and her ultimate, Freezing Field, is a powerful channeled ability that slow enemies and deal massive damage, but leaves Rylai vulnerable while casting.