Spellcasting. Tempest has innate spellcasting from being a Fire Genasi. Constitution is her spellcasting ability (DC 13, spellcasting modifier +5). She can cast the following spells:

Cantrips. (At will) Produce Flame
First Level. (Once per long rest) Burning Hands

Sneak Attack. Once per turn, Tempest can deal an extra 4d6 damage to one creature she hits with an attack with a finesse or ranged weapon if she has advantage on the attack roll. She doesn’t need advantage on the attack roll if another enemy of the target is within 5 ft. of it, that enemy isn’t incapacitated, and she doesn’t have disadvantage on the attack roll.

Fast Hands. Tempest can use the bonus action granted by her Cunning Action to make a Sleight of Hand check, use her thieves’ tools to disarm a trap or open a lock, or take the Use an Object action.

Second Story Work. Climbing doesn't cost Tempest extra movement, and when she makes a running jump, the distance she covers increases by +5 feet.

Evasion. When Tempest is subjected to an effect that allows her to make a DEX saving throw to take only half damage, she instead takes no damage if she succeeds on the saving throw, and only half damage if she fails.

Expert Tavern Brawler. Tempest is an expert with improvised weapons. Her unarmed strike and improvised weapons deal 1d6+4 physical damage of your choice and are considered finesse weapons. When she hits a creature with an unarmed strike or an improvised weapon on her turn, she can use a bonus action to attempt to grapple the target.