Path of the Thunderscreamer

Barbarians already tend to scream and bellow when gripped with the throes of battle, but few such warriors have realized the potential of the scream, or refined it into a formidable addition to martial combat in the same way that those who observe the Path of the Thunderscreamer have done. These formidable combatants are able to bellow forth mighty screams which, when coupled with the magical breathing techniques and special breath training these warriors undergo, acts in tandem to become powerful magical screams that assault enemies with thunderous force, or war cries that bolster their allies in combat, urging those companions to embrace their more feral battle urges, as well. Few barbarians can match the assault capability of the Thunderscreamer, and since their voice resonates with the fury of nature itself, their magic is actually quite nearly unstoppable.

In Avalestra, the Goliath who patrol the outskirts of the Wastelands make good use of this path, teaching it via word of mouth to any young initiates willing to serve a "fultram" with them. A fultram being the length of time it takes for a warrior to vanquish twelve worthy threats. Many of the last remaining humans who fled from Antargen Ares embraced this lifestyle, as well, but in the years intervening, many of those have been lost in conflict with the horrors of the wasteland or they've moved on from such obviously dangerous lives. Nonetheless, this particular tradition of teaching remains strong amidst many clans of savage peoples like the Tauros. The Shulwaine Maenad, who seem to have a particular proclivity for it, have recently been teaching their warriors in this path, in addition to their Path of Wilders, and the number of threats they can oppose have dramatically increased as a result.

Potent Scream

3rd level Path of the Thunderscreamer feature

At 3rd level, you gain the ability to focus your shouts into an offensive magical sonic attack, usable while you Rage to be able to blast your foes with magically damaging screams in addition to your martial skills. You gain a Scream Score, and its maximum value is equal to twice your proficiency bonus. Starting at 3rd level, while in a Rage you may use an action to cast the Thunderwave spell by spending 1 Scream Point. This casting of the spell does not expend spell slots, does not have somatic components, cannot be Counterspelled, and is cast with a spell save DC equal to 8 + your Proficiency bonus + your Constitution modifier. When you cast this spell, you may spend a number of additional scream points equal to half your character level, rounded down, minus one (minimum 1), and for each point spent this way, you may improve the spell level of this spell by 1 (to a maximum of 8 points spent). Your Scream Score resets to its maximum value when you finish a long rest.

Additionally, your voice is capable of being very loud, and any range at which you could normally be heard is doubled if you choose to shout. If you are attempting to shout down a creature in an effort to intimidate it, and that creature can hear you, you gain advantage on your Charisma (Intimidate) check.

Battle Cry

6th level Path of the Thunderscreamer feature

At 6th level, you are able to issue forth a bellowing scream which reinforces your allies' resolve in a fight. As a bonus action once per Rage, spend 2 Scream Points and other creatures of your choice who can hear you within 30 feet gain temporary hit points equal to half your barbarian level rounded down, and they also gain a 1d4 bonus to attack rolls. When you use this feature, you regain 1d8 + your Constitution modifier hit points. These benefits last until your Rage ends.

Additionally, your breath training and nigh-superhuman lung capacity now allow you to hold your breath for twice as long as normal before you drop to 0 hit points and begin dying.

Piercing Scream

10th level Path of the Thunderscreamer feature

Starting at 10th level, you gain the ability to bellow a terrifying scream which may cause your enemies to break and flee. While in a Rage, you may spend 3 Scream Points and an action to cast the Fear spell without expending spell slots, without somatic or material components, and this spell cannot be Counterspelled. The save DC for this spell is equal to 8 + your Proficiency bonus + your Constitution modifier.

Additionally, when you are Raging, you cannot be silenced (and are immune to magical silence effects like those caused by the Silence spell), and also you can always cast spells using Scream Points despite your environmental conditions (even underwater). Only a total void space with no atmosphere surrounding you could cause your spells cast to be nullified.

Devastating Roar

14th level Path of the Thunderscreamer feature

At 14th level, you become capable of unleashing a devastating thunderous scream, laden with innate primal power, and your strikes themselves can blast forth with thunderous might. As an action during a Rage you may spend 5 Scream Points to cast Destructive Wave without expending spell slots, and this spell cannot be Counterspelled. The save DC for this spell is equal to 8 + your Proficiency bonus + your Constitution modifier.

Additionally, if you roll initiative and have no Scream Points remaining, you gain 4 Scream Points.

Lastly, you may spend 1 Scream Point when you hit with a melee weapon attack to cause that attack to be treated as a successful hit with the Booming Blade cantrip, which you immediately cast upon the target of that attack. This casting of Booming Blade cannot be Counterspelled.