Tempest

Among the genasi, there existed those that could manifest more than one elemental soul. They were known as Elemental Tempests, or Tempests for short. An unusual talent amongst their race, as genasi are only born with one elemental manifestation based on their heritage.

Those with the gift to manifest additional elemental souls usually do so based on their surrounding environmental conditions or hidden ancestry. An even rarer breed of genasi can manifest more than one soul at once. Tempests embrace the chaos of their physical nature, and are passionate individuals capable of vast power and unusual versatility. 

Select a new genasi elemental manifestation. You gain the increased ability score of the selected manifestation passively across any expressed manifestation (Add related ability score increase to 'Other Modifier' of appropriate stat under Abilities section of the character sheet). When you take a long rest, you can adopt this new elemental manifestation instead of the one you had been exhibiting, gaining access to the currently expressed genasi traits. You can also revert back to your birth-given elemental soul upon a long rest.

You can take this feat multiple times, choosing a new manifestation each time. When you take a long rest, you can choose to switch between any of the elemental manifestations you know.

*Changes not reflected in the DnD Beyond UI. Refer to the Feats section of your character page for new genasi traits*