This one eye tends to be your biggest downfall. you lack depth perception and have a disadvantage on all ranged attacks. 

an enemy may also directly target your eye, if your eye is attacked the enemy has disadvantage on the attack and you may make a constitution saving throw against it, but on a successful hit you are blinded and must attack at the DM's discretion.

Your large size and tough skin make you a force to be reckoned with in melee combat. you take half damage from all physical attacks.

you are a wonderful smith and can stand extreme heat with no issue. You have immunity to fire and proficiency with smith, artisan, and other crafting tools.

your strength can reach 30 instead of 20, +5 strength and advantage on all strength throws/saving throws.

you may also try and crush an enemy in your giant state and they must make a saving throw against your strength modifier plus 10 or take 1d20 bludgeoning damage.

you have a -2 in dexterity and disadvantage on all dexterity throws while in your giant state.

you also require a full turn to stand up.

Your intelligence can not exceed 12 and you have a -5 to intelligence and have disadvantages on most intelligence checks

Do to your races notorious reputation people don't trust you, -5 to charisma and disadvantage on charisma throws.

You mat change your size from 30ft to 7ft to help you in smaller areas.

you can breathe underwater

You can mimic the voice of any person you have heard and can instantly succeed a bluff check involving that voice if you are out of sight.

you can speak read and write giant and common, you also understand any language the predates civilization.