Seventhborn - Crystal Skins

First mistaken as moving crystal formations the Seventhborn are a rather extreme and peculiar race, even compared to the Secondborn . While bipedal in shape they have a rather distinct form, they have a tail but it’s covered in these crystals they possess and even acts as a weapon as it’s both spiked and club shaped due to crystal growths. Their extremities have crystals as well typically leaving the lower halves fully covered. These same crystals cover their backs and spine. This also includes their heads which can seemingly close around the face like a helm to protect the face. Scale-like crystals protect their torso and thighs, and any remaining areas unprotected from raw crystal. Some express extreme crystal growth when under great stress but the excess falls off when they grow calm. Pureblood

+2 Constitution
Strengthening Shards: Seventhborn are known for their incredibly strong crystals, to the point in or out of armor these crystals serve to better protect the pureblood. Seventhborn may add their ((Constitution Modifier or Dexterity Modifier of Strength Modifier)/2) Armor Class.
Crystal Armor: A pureblood may enter a bodily stressed state. During this time their crystals grow across their body fully to protect them. During this time they gain temporary health points equal to (Proficiency Modifier x Constitution Modifier or Dexterity Modifier of Strength Modifier). Their additional armor becomes instead simply (Constitution Modifier or Dexterity Modifier of Strength Modifier) and any melee attack against them provokes a dexterity saving throw. The DC of which is (8 + Proficiency Modifier + Constitution Modifier or Dexterity Modifier of Strength Modifier). If succeeded against the attacker takes half damage otherwise they take (Proficiency Modifier)d6 + (Constitution Modifier or Dexterity Modifier of Strength Modifier). This form last (Proficiency Modifier) minutes or until the temporary hp is reduced to zero. A pureblood can use this ability (Constitution Modifier or Dexterity Modifier of Strength Modifier) times before needing a short rest to gain back half of the missing charges rounded down or a long rest for all.

Halfblood

+1 Constitution
Fluctuating Shards: A half blood has (Proficiency Modifier) crystal charges. One charge can be used to cause violent shard growth temporarily whenever attacked for (Proficiency Modifier) turns. A melee attacker must make a dexterity saving throw against a DC of (8 + Proficiency Modifier + Constitution Modifier or Dexterity Modifier of Strength Modifier). If they succeed they take no damage. If they fail they take (Proficiency Modifier/2 Rounded Down)d8 + (Constitution Modifier or Dexterity Modifier of Strength Modifier). The other use for a crystal charge is to grow a serious array of crystal on their tail. The tail is used as a finesse or strength based weapon and deals (Proficiency Modifier)d12 + (Constitution Modifier or Dexterity Modifier of Strength Modifier). It will shatter after making one successful attack and if it remains a halfblood's speed is reduced by half and they have disadvantage against dexterity checks. Half of missing charges rounded down are regained during short rest, and all are regained after a long rest.