Gathering Storm cannot be supported by Despoiler Support and lacks the duration tag.

Despite creating shocked ground on a perfectly timed dash, the quarterstaff skill Gathering Storm is not compatible with Despoiler Support, which increases the duration of ground surfaces created by supported skills. Additionally, it nether lists the duration of it's shocked ground in the tooltip, nor has the duration tag. Given that other skills that create elemental ground effects, including Lightning Warp, have the duration tag and a listed base duration for their ground effects, this appears to be an unintentional result.

Additionally, since it's come to mind, Gathering Storm is also classified as a Strike skill, has a listed increase to melee strike range, and can be supported by Strike-exclusive support gems- however, no part of the skill actually seems to function as a strike- it does not build combo, for example.