Mystic Twister

Acquisition
Skill trainers Hero skill trainers Signet of Capture
 * Nightfall
 * Medando (Yohlon Haven)
 * Kenohir (Command Post)
 * Iasha (Wehhan Terraces)
 * Wedende (Dajkah Inlet)
 * Nightfall
 * Warden of Whispers (Chantry of Secrets)
 * Eye of the North
 * Facet of Spirit (Varajar Fells, Arbor Bay)

Trivia

 * Along with this skill, Mystic Sandstorm and Test of Faith are the only spells that require adrenaline instead of energy.