Flame of hatred

Hate is a devouring flame that spreads like a disease. Some are more victims of it than others, but rare are those who develop such hatred in their hearts. This barbarian archetype is one of those individuals cursed by their own hatreds, which is etched into their souls. His rage is demonic and gives him considerable power, but at a price to pay, because he risks being consume by the flames of hatred.
This savage and cursed fighter is forced to meditate when he can to dim the flames that burn within his heart, but he can never extinguish them and never truly find peace. His hatred grow more and more, until it eventually transforms him, changing him into a bloodthirsty demon.

Hatred in the eyes:

At level 3, your eyes glow with a barely visible ominous light. You gain the eldritch invocation « Devil’s Sight » and proficiency in intimidation. If you already have this proficiency, you gain a +1 to charisma. Some people know that hate can manifest in this way, so they can recognize you as someone cursed by the flame of hatred.

Anger and flame:

At level 3, the rules regarding your rage change:
When you find yourself in the thick of battle, you are driven by demonic hatred. On your turn, you can use a bonus action to enrage. Your breath emits ashes, your eyes turn red, and your voice becomes demonic.
At the start of your rage, you can deliberately suffer 1-3 levels of hatred if you wish. While enraged, and if you are not wearing heavy armor, you gain the following benefits:
-You have advantage on Strength checks and Strength saving throws.
-When you attack, regardless of the type of attack, you gain a bonus to damage rolls. This bonus increases at the same time as your level (see the Barbarian's evolution table, rage damage column).
-You become resistant to bludgeoning, piercing, slashing, and fire damage. You also not suffer from extreme heat or exhaustion. Likewise, a magical effect cannot put you to sleep. You cannot be charmed or terrorized while enraged. If you are already Charmed or Terrified when you enter a rage, the effect is suspended for the duration of the rage
-You can cast the spell "Fire Bolt", your spellcasting ability is constitution.

However, while enraged, you cannot cast spells or focus on spells, even if you normally have the ability. The spell given to you by this rage is an exception to this rule.

Your rage lasts 1 minute (10 rounds). This state ends early if you're unconscious or if your turn ends and you haven't attacked a hostile creature or taken any damage since your last turn ended. You can end this state during your turn without any action needed. When your rage ends, you must make a DC 10 Wisdom save throw. If this check fails, you take one level of hatred. (See "Consumed by Hate") Once you have entered a state of rage the number of times allowed by your level (see the Barbarian evolution table, rages column), you must complete a long rest before you can enter a rage again.

Consumed by hate:

This barbarian archetype can suffer levels of hatred at the end of its rage if it fails its Save throw or kills a defenseless, non-hostile humanoid target. This mechanic is like the level exhaustion mechanic, but the effects and the way to get rid of these levels are different. Depending on the level of hatred you suffer, the following effects are applied:

Level 1: You have an advantage on your Charisma or Strength tests based on Intimidation.

Level 2: Any creature, allies included, within a 10 feet radius other than you suffer 2 fire damage each turn while you are enraged. However, you suffer disadvantage on any Charisma check that is not based on intimidation.

Level 3: If you are not enraged and you are directly attacked, you must make a DC 10 Wisdom saving throw. If you fail, you enrage, and those even if you normally cannot do it. If you enter a rage this way and there are no enemies around you, you are forced to try to attack the nearest creature. However, you regain control of yourself after performing this attack, whether it is failed or successful.

Level 4: When you enter a rage, the light around you dims, creating a shadowy area with 40 feet radius around you. Plus, all fire damage you inflict is increased by 1. You also become immune to fire damage, even when not enraged. However, if you fall unconscious, you must make a DC 10 Wisdom saving throw when you recover. If you fail, you suffer a level of hate.

Level 5: When you enter a rage, you are now considered has a demon and your alignment changes to chaotic evil. Your rage can no longer end prematurely, unless you are knocked unconscious, and no longer ends when you wish (it lasts for 10 rounds). If there are no enemies to attack, you will have no choice but to attack the creature closest to you.

Level 6: When you enter this level, you have to make a wisdom saving throw. If you succeed, you return to the level 5 of hatred. But if you fail, you completely and forever erase yourself in favor of your demonic hatred. Your body is completely covered in flame, so much so that people can't even see your face. You go into a permanent rage and now live only to cause death and destruction in your path. There is no turning back possible. When a flame of hatred barbarian reaches this stage, the character is lost. he becomes a monster, and the DM takes control of him.

Ritual meditation:

At level 3, during a rest, whether short or long, you can perform a quiet and soothing activity of your choice that helps you find peace (Cooking, meditation, sculpture...). You don't have to master this activity, only its soothing aspect counts.

When you perform this activity, you must make a DC 10 Wisdom saving throw. If you succeed, you lose one level of hatred. You can lose 2 if you wish, but only if you perform this activity during a long rest. If you fail, your level of hatred does not change. Although this is a saving throw, people you trust can help you with it, giving you an advantage on this test.

Think of it as a calming activity in which one of your fellow adventurers can help you to increase your chances of finding peace.

Reckless fire:

At level 6, your reckless attack give you advantage to perform any kind of attack, regardless of their type. Likewise, when you perform a reckless attack, you inflict bonus fire damage equal to your proficiency bonus. This bonus damage can be use only once per turn.

Overcome hatred:

At level 10, you have resisted your inner demon long enough to gain proficiency on Wisdom saving throw. Plus, the resistance to fire and from extreme heat gained when you rage are now active even out of rage.

Hell on earth:

At level 14, While enraged, you can now use "Fire Bolt" without any components. The flames just come out of your body to burn your enemies.
You also gain the ability to use this spell as a bonus action a number of times equal to your proficiency bonus. You must finish a long rest to recharge this ability.