Path of Retaliation

being a people that wanted to emulate the hedgehogs natural ability to deter predators, these people decided to alter their body in many ways this lead to the once very intelligent people to become dumber and more prone to fits of rage. But they did succeed to alter themselves, now long dark spikes grow from their skin making it impossible to wear armour. 

Spiked Skin

When you choose this path at 3rd level, your ancetral heritage to these ancient poeple are reviled as over the course of 3 days as spikes painfully grow out of your skin.

While raging your AC is reduced by half and When you are hit with a melee attack you can use your reaction to cause the attacker to take damage equal to half your original AC was before you entered your rage + proficiency modifier.

Harden Spikes

Beginning at 7th level, you are able to use Spiked skin twice in one turn unless you use your reaction for something else and your Spikes count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Curl Up

While you are raging. You can take an action to curl up into a rough ball shape doing so reduces your AC to zero and adds it to you're spiked skin damage and if creature is moving within 5 ft of you it must succeed on a Dexterity saving throw or take damage from you're spiked skin. A creature moving through the area at half speed doesn't need to make the save.

DC equals 8 + proficiency + DEX modifier

Spiked Retribution

Beginning at 14th level, you are able to use Spiked skin four times in one turn unless you use your reaction for something else.