Insectoid path

Metamorphosis
At level 3, while choosing this path, the barbarian while raging can transform and becoming an hybrid with
different bugs. While doing this he has advantage on costitution throw and a +1 in CA. At level 11 the CA
bonus become a +2.
Butterfly effect
Since level 6, grown butterfly/dragonfly’s wings on the back,so he can enter in a flying state and the creature over 18 meters (60 foot) get disadvantage on rolls to attack flying creature. 
Furius swarm
At level 10, choose a bug that will give you different
privilege, it give you a few physical changes while you’re in metamorphosis. The bug can be choose by the most common in the region he lived or by his fighting style.
Wasp. The barbarian get 2 bonus damage on piercing damage and get the anarmed move sting, it grow a sting on a part of his body of his choice that do 1d6 piercing damage. The bonus damage increase at the superior levels:3 at level 13, 4 at level 16, 5 at level 20.
Mantis. The barbarian get competence in stealth,get the anarmed move raptatoria paw, two mantis like appendages grow on barbarian’s shoulders dealing 1d8 cut damage and creating a grapple state. The damage increase at the superior levels:2d8 at level 13, 3d8 at level 16, 4d8 at level 20.
Beetle. The barbarian and all the creature that he
wants get 2 temporary hit points, he become resistent to fire damage and resist to the extream heat of the desert. The bonus hit points increase at the superior levels:3 at level 13, 4 at level 16, 5 at level 20.
Insect king/queen
At level 14, the trasformation come to his perfect form granting extra ability based on the choosen bug.
Wasp. When the barbarian do piercing damage, ha
can ad an additional poison damage of 1d4 and the
creature hit get poisoned. The poison deal 1d4 at the end of the turn for each turn passed since it get
poisoned. for remove the effect the creature have to do a saving throw on constitution.                            Mantis. The barbaria became stronger as his grapple now the raptatoria paw have a range of 3 meters(10 foot) and when the kill a creature while in a grapple he restore hit poits equal to streight modifier+costitution modifier+6.
Beetle. The barbarian become able to create a block of dirt 1,5 meter of edge(5foot) or a orb 1,5 meter of radius (5foot), if they’re thrown the range is 5/15 meters(16/50 foot) dealing 1d6 blunt damage.

Level 3: Metamorphosis

At level 3, while choosing this path, the barbarian while raging can transform and becoming an hybrid with different bugs. While doing this he has advantage on costitution throw and a +1 in CA. At level 11 the CA bonus become a +2.