Path of Dancing Edges

With a goal of forging valkyrie better able to shepherd Acheron's tribes (while causing as little injury to patriarchal egos as possible), Luthic inspires her priestesses to set promising initiates on a path of "dance."  Practitioners of this brutal choreography rage with artistic fury.

Although the goddess and her clergy only pretend to humor orcish gender sensitivities, it would be unusual for a male orc to seek the mantle of "dancer" over "warrior."  Half-orcs are less burdened by social roles (particularly when living among humans).  Under truly extraordinary circumstances, the Cave Mother might even induct a dancer with no orcish blood at all into her "troupe," but such an initiate would be required to show an unimpeachable history of loyalty to her people's cause.  Once the runic eye blinks open, there will be no fooling her -- and the axe that binds can also sever.

Bound to the Edge

Choosing this path at 3rd level, you gain proficiency with Smith's Tools and the Performance skill.  Cutting your hand with a ceremonial knife, you sacrifice blood to ore before smelting it, then hammer out the steel of a greataxe blade.  After the axe head is shaped and mounted, you dance with it beneath successive crescent moons.  As Luthic's priestesses chant invocations, the Cave Mother imbues your weapon with sentience.  When the ritual ends, a runic eye blinks open on the steel.

Your rune axe gains a magical enchantment equal to half your proficiency bonus rounded down (e.g. +1 at 3rd level), increasing as you rise in level.

You may communicate with the weapon telepathically across any distance, ignoring planar boundaries.  The axe's spirit possesses Intelligence, Wisdom, and Charisma scores equal to 10 plus half your Barbarian level rounded down.  These also increase as you rise in level.  The spirit is proficient in History, Religion, and Nature, uses your proficiency bonus, and possesses expertise on matters related to orcs.  

You may call your rune axe to your hands from anywhere as a non-action.  Even if somehow destroyed, Luthic will reform the weapon and return it to you.  The axe's spirit is an extension of her will.  At the Cave Mother's discretion, descendants of dancers who rose to valiant service in Acheron may find their own rune axes occasionally enhanced with properties from the ancestor's now sacred weapon.  If the goddess determines one of her dancers no longer follows the path truly, however, she will call the weapon to herself and keep it until proper atonements have been made.

Runes of Power

Luthic inscribes a rune on your axe, allowing it to channel her blessings.  At 6th level, you may direct the spirit of your weapon to cast shield of faith on you as a bonus action once per short or long rest.  The spirit is able to concentrate even when you are not.

At 9th level, the Cave Mother inscribes an additional rune on your axe, allowing you to direct it to cast freedom of movement on you once per long rest.

At 12th level, a rune appears allowing your axe to cast commune once per day.

The final rune appears at 15th level.  Your axe may cast etherealness on you once per day.

Sharp as the Cave Mother's Claws

Luthic blesses the edge of your rune axe.  At 10th level, the weapon gains the properties of a sword of sharpness.

Dancing Crescent

At 14th level, you may hurl your rune axe at a target up to 30 feet away as a bonus action.  You do not suffer disadvantage for making this attack while in melee combat.  Dancing by Luthic's grace, the blade makes one melee attack against each opponent in its 5-foot wide path as if you were wielding the weapon directly.  The axe returns after reaching the end of its path, repeating its attacks on the way back.

Once you use this ability, you may not do so again until after a short or long rest.