Crystal Warrior

Crystal Warriors know more about abstract magical theory than most rangers, and they can bend the laws of matter in unique ways. A crystal warrior is affiliated with one kind of crystal, using it to fuel their magic. 

Level 3: Nature of the Arcane

You can use a crystal as a spell casting focus for your ranger spells. Optionally, you can have crystal weapon(s) (and shield), which could work as a spell casting focus if the DM allows. 

You can also make an arcana or nature check that would normally take an action as a bonus action.

You can also use your bonus action to gain advantage on an arcana or nature check that you don't need to spend an action on. You can do this a number of times equal to your wisdom modifier, and you regain all expended uses upon completing a long rest. 

Level 3: Fracturing Shot

You gain a different way to attack. Instead of making a normal attack, you can expend a spell slot to make a Fracturing Shot. When you do this, you fire an arrow or throw a weapon (or, heck, make a melee attack if you want), and the damage-dealing object, whatever it is, splits into d6 crystal shards. Direct these shards towards one or more creatures within 40 feet of you, hitting them and dealing d6 damage for each one. The damage is of the type of your choice from among psychic, force, poison, or, if you want to be lame, piercing. If you want, the weapon reforms after this happens. If it was a melee weapon, it does so back into your hand.

At Higher Levels. When you use this ability using a spell slot of 2nd level or higher, the spell creates more shards: a 2nd level spell slot makes d8, a 3rd makes d10, a 4th makes d12, and a 5th makes d14 (this can mean 3d4, as that has the same average, or roll a d20 and reroll it if it is higher than 14).

Level 7: Defensive Fracture

You can magically shatter an enemy's attack. As a reaction to an enemy hitting you with an attack, you shatter what they attacked you with into crystal shards, canceling the damage and direct the shards toward a creature of your choice within 20 feet of you, or 40 feet if the original attack was ranged. Roll a number of d4s equal to twice your proficiency bonus and deal that much damage to the target. The type of damage is your choice between psychic, poison, force, piercing, or the same type of damage the original attack was going to deal. 

If the thing you shattered was not a projectile, it reforms after this effect.

Once you use this reaction, you can't use it again until you complete a short or long rest. You gain an additional use of it when you reach 15th level in this class. 

Level 11: Experienced Shatter

You are so proficient with creating splintered shots that every time you make an attack you make one additional shard. Even if you didn't use Fracturing Shot, this will still create a shard. 

Level 15: Final Burst

When you deal the finishing blow to a creature, you can shatter it into pieces that look like your shards, directing them to deal 2d12 damage to up to two creatures of your choice and letting up to three creatures of your choice regain d12 hit points. In order to target a creature with this, they have to be within 30 feet of the creature you exploded. 

What the creature you exploded looks like afterwords is up to you. 

Once you use this ability, you can only use it once an hour has passed.