Path of the Attacking Titan

Barbarians who walk the Path of the Titan draw their rage from an anchient blessing (or curse?) running within their bloodlines. That titanic creature bursts forth in the throes of rage, physically transforming the barbarian.

Barbarians inherent to this power are often feared for their abilites, as the form they transform into is hulking, intimidating and ferocious. What makes this form even more terrifying is the fact that the user must either harm themselves or get hurt by others to be able to transform.

Enhanced Regeneration

When you choose this path at 3rd level, you gain the ability to quickly recover from damage you've received. On the start of each of your turns, you can choose to regain an amount of hitpoints equal to your proficiency bonus + your constitution modifier. You can use this feature a number of times equal to your proficiency bonus. You regain all expended uses at the end of your next long rest.

Form of the Titan

When you choose this path at 3rd level, you gain the ability to transform into your titanic state.

When you start raging, you can harm yourself, maybe with an unarmed strike or a weapon attack, and transform into your titan state.

While in your titan state, you gain the following benefits:

- Your size becomes one size category larger (min. Large). This size bonus increases by 1 at 10th level and at 14th level. You can choose to stay at a smaller size (min. Large), for example when there isn't enough space to transform into a larger form. Your worn gear melds into the new form. You can't activate, use, or wield any of your equipment in this state. Benefits of magical items, such as ability score improving items, still apply. 
- You gain the 'Giant' creature type while you remain in this form.
- Your unarmed strikes become much stronger, turning them into 2d6 + your Strength Modifier for the duration. This damage dice increases to 2d8 at 6th level, 3d6 at 10th level, 3d8 at 14th level, and 3d10 at 18th level.
- You gain temporary hit points equal to ( 3x your barbarians level ). When you have temporary health points remaining at the end of your rage, they vanish together with the titanic body. 

You can also end your rage on your turn as a bonus action, ending your transformation.

Hardened Skin

Starting at 6th level, you've learned to control the hardening process in your titanic body, empowering your attacks and defense. Your unarmed strikes now count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Additionally, you can use your reaction when you are attacked to harden your skin, increasing your armor class by 5 until the end of the attacking creatures turn. You can use this defensive feature a number of times equal to your proficiency bonus and regain all uses at the end of your next short or long rest.

Intimidating Presence

Beginning at 10th level, your mere presenece while in your titan state can be frightening. When you are in your titan state, every enemy creature that can see or hear you, must succeed on a Wisdom saving throw (DC equal to 8 + your proficiency bonus + your Charisma modifier) or be frightened of you for 1 minute. On subsequent turns, the creature can repeat the Wisdom saving throw to end the effect early.

If the creature succeeds on its saving throw, it is imune to this feature for 24 hours.

Impactful Blows

Starting at 14th level, your unarmed strikes become powerful enough to shatter the earth. When you attack a creature that is atleast one size category smaller than you with your unarmed strike, you shatter the earth around the target, attacking all creatures within 5 feet of your target. Creatures in the area must make a Dexterity saving throw of DC 8 + your Strength modifier + your proficiency bonus. On a failed save, the creature takes the full bludegoning damage you dealt with your unarmed strike, crushing them in debris and are knocked prone.

On a success, the creature only takes half of the damage and isn't knocked prone.