When Seattle’s Sunn O))) (Pronounced Sun) takes the reins of any stage, a cloud of fog appears, and the Drone Metal collective is off to the races in a slow and steady spectacle. The Washington State joint is a complex performance oddity. Equipped with a dozen or so amplifiers stacked to the level of ancient monuments, the sonic abilities of the Pacific Northwest group know no end. On Wednesday night at Paramount Theater in Austin, Sunn summoned a mystical performance that showcased their unending ability to create glacial soundscapes that made the audience’s jaws drop to the floor with their slow-burning modus operandi.