Uncontrollable rage

You are unable to trigger your rage intentionally.

You have an adrenaline meter which increases or decreases based on what happens to you. The level can be positive as well as negative. You start each battle (day?) at 0.

When your adrenaline meter reaches certain levels, your mental state changes:

• -12: Zen Mastery: on each of your turns, you gain an extra attack for 1d6 rounds
• -8: Trance: you gain a temporary +2 bonus to your AC until your adrenaline reaches 0 again
• -4: Tranquil: you gain 1d12 temporary hit points
• +4: Angry Rage: you trigger your rage and choose your beast origin
• +8: Furious Rage: you add 1d4 bonus die to your damage
• +12: Frenzied Rage: you lose control over your body. On each of your turns, you choose your target (which may be an ally) by rolling an appropriate die. You attack this target, using any extra attacks that you would use on a regular turn. You get resistance to all damage types

Your adrenaline changes 

• Each time you take a hit: +1 adrenaline
• Each time you make a successful attack: +1 adrenaline
• As a bonus action, you can control your breath: -1 adrenaline
• As an action, you channel your chakra: -2 adrenaline
• As an action, you make a war cry: +3 adrenaline
• An ally can use their action to whistle, sing a song, recite lyrics or give another signal that you choose together with your DM: -3 adrenaline