Little Giant. You have proficiency in the Athletics skill, and you count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.

Titan's Endurance. You can supernaturally draw on the might of your Giant ancestors to shrug off harm. When you take damage, you can use your reaction to roll a d12. Add your Constitution modifier to the number rolled and reduce the damage by that total. You can use this trait a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Aquatic Homelands. Many Storm Giants lived deep below the ocean's surface. You can breathe both air and water, and you have a swimming speed equal to your walking speed.

Stormborn. Your ancestors considered tempests their kindred and became invulnerable to their wrath. You are resistant to lightning damage. Alternatively, you gain resistance to thunder damage and have advantage on saving throws against being deafened.