Path of the Horn

The hunting horn is a blunt weapon that can bestow positive status effects on yourself and your allies. Use it to perform melodies that can boost attack power, restore health, and grant other beneficial effects. Path of the Horn barbarians make full use of this strange horn to buff allies and dissuade enemies 

Horn Technique

Starting when you choose this path at 3rd level, you can turn regular two handed weapons into works of art. While wielding a 2 handed martial weapon, you can spend a minute to turn it into a hunting horn variant;  affixing and modifying the weapon so that it works with your usual class abilities. When swung, your horn makes noise, called a note, and deals bludgeoning damage instead of it's usual damage type. There are three basic types of notes:

Sonic - When you play a sonic note, your current attack deals one additional die of thunder damage. This is improved to two additional dies at 6th level, three at 10th level, and four at 14th level (in this subclass).

A Note - You play a note that when strung together, makes a song. Songs affect a number of creatures you can see equal to your charisma score, including yourself.

F Note - You play a note that when strung together, makes a song. Songs affect a number of creatures you can see equal to your charisma score, including yourself.

 

You begin by learning two basic songs. The names of the songs will also describe which notes and in what order a song must be played to gain it's benefits (you gain the effects after making the final required attack):

AA: Creatures affected are under the spell bless, but it is not cast and does not require concentration

FF: Creatures affected are under the spell bane, but it is not cast and does not require concentration

Sound Amp

Beginning at 6th level, you learn songs and techniques to smash apart your foes with music. When you score a critical hit while playing a note, you can make a weapon attack with your horn, as long as that attack plays the next note of a song you have learned. This special attack cannot proc another attack in this way. You also learn two new songs:

AAF -  Each target’s hit point maximum and current hit points increase by an amount equal to your charisma score plus your level for one hour.

FAF - You may choose the same creature as a target for this song, and it's effect stacks. When you would deal thunder damage, you deal 1d4 more damage, to a maximum of 5d4 additional thunder damage. Song lasts for one minute.

Knockout Strike

Beginning at 10th level, you master how to use your heavy weapon to knock out opposing foes. Whenever an attack with your hunting horn would finish a song, the creature hit must make a concentration check versus the damage dealt by that attack; on a failure, the creature is stunned until the end of it's next turn. You learn two additional songs:

AFFA - Choose a weapon trait. Affected creatures who make an attack with that weapon trait may add the effects of the spell Booming Blade onto the attack, without casting the spell.

FFFA - Choose a condition immunity. Creatures affected lose that condition immunity if they had it. A creature who loses an immunity this way regains it in 1d4 minutes. 

 

Note: Concentration checks are against half the damage dealt, with a minimum DC of 10.

Vibe Zone

Starting at 14th level, you emit downright succulent Vibes while your hunting horn is alight with song. While holding your horn, the vibes take form as an aura with a 30ft radius, and grants creatures within it a different effect, depending on their disposition towards you. You may choose to forgo some or all of these effects on a creature.

Friendly - You gain a +5 to your passive perception, investigation, and insight. You gain immunity to thunder damage

Hostile - When you enter the aura or start your turn there, you are affected by the Elemental Bane spell (assuming you fail the save, as if you had cast it. DC = to barbarian level)

You also learn two ultimate songs, the greatest and longest songs in your arsenal:

AAAFA - The next time in 6 hours that the affected creature would drop to 0 hit points, they instead drop to one and this effect ends. 

FFAAF - When this song is played on you, Select a creature you can see, and make a charisma skill check of your choice, contested by that creature's insight check. On a successful contest, it's constitution saving throws and concentration checks have a -5 to the roll for one minute, and you gain a +5 to concentration checks, stacking up to 3 times.