An easy thing to banish, but a cruel fate to the soul, for the other half cannot survive on its own. They need to be made whole once more.
A task is set; to merge the fragments. It is no feat which can be done in the afterlife, for that is the domain of others, where a shaman is only a guest. The other fragment needs to be brought back and a haunt reformed as a haunting soul. In part… it would mean strengthening the spectre of the woods.

The first task: Crossing the veil of death.
In the secluded forest by the haunted shack, stones are lain in circles and intricate patterns, enveloping a freshly dug grave. Rocks dictate the passage the spirit will take and will guide the one towards the place he desired to be in.
At the centre, a shallow open grave, by it, runes of warding and recall, a way to restore the spirit back into its body once the task is complete. A shaman lies inside the shallow grave, surrounded by stonework and rune, face covered by a death-mask of bone, adorned in robes of the dead, black as the veil, tattered as the spirit he hunts.
He takes a knife and lets the jagged edge cut deep wounds across his wrists, deep enough to bleed, but narrow enough to make the process slow, lingering at the very edge of death, striding just barely across the veil, his body growing cold, his mind, unshackled by the flesh, drifts across the patterns of stone towards the veil.

All Is dark beyond the veil, a shadow hard to pierce, but the guiding stones prove to be precise. Just at the threshold of death remains a fragment. A silvery sliver, a soul lain bare to his gaze, a thing not a spirit, nor an object, essence of life made manifest. So easy to consume, so easy to use… It is in essence raw power for those willing to exploit it… but it will not be so today.
Freshly drawn tattoos across the shaman’s torso form a cage, a containing ward, a chest designed for one specific thing… that very fragment. He reaches for it, not with hands, but with sheer will, he drags it close… The sliver turns into a silvery mist and drifts… only moments away from him, but every moment at the brink of death could be the last.
The Shaman inhales, sharply, deeply, dragging the silvery mist into himself. The very act would join the fragment to his own soul, yet the runes of containment were drawn to the precise rite and lore he was taught in, holding for moments, his own flesh serving as a soul-gem for this fragment, every moment, he resists the urge to simply consume the raw soul-mana. He got what he came for. It is time to recall.
Shaman turns his spirit form, from silvery spectre it turns into a golden radiance, wings of sunlight spreading behind his back as he soars like an eagle, bathed in gold, through the darkness, away from the veil. Beyond the realm of senses, a burning trail remains. It will heal, but his footsteps will be seen by those who pass, for his need is great. Moments remain till he would be gone for good, as his spirit-self soars back towards the world of the living.

Across his near-dead corpse… a spectre looms. The lost soul, there only in part, longing, hungering for the soul he no longer has. He had smelled the blood and a near-dying man. The spectre looms across the body of the shaman, ready to enter it… to defile the lingering trace of what it once possessed. Spectre reaches out… through the flesh, slowly gripping the heart, which slows its beat… Moments until the shaman would be no more, spectre indulging its mindless hunger.
As a burst of radiance to the spectre, a golden light shining from the body, unseen to mortal eyes, as the spirit-form races back from beyond the world of the living, carrying the fragmented soul. A surprised spectre now sensing another present in the body lets out a wail, forcing its will into that very same body, ready to fight for its possession!
The shaman gives in, does not resist the possession attempts as the spirit enters, now two souls sharing a body. His own, and that of a broken man, cloven in two. Regaining some control of his limbs, the shaman quickly gestures the warding rites and uses the runes about the shallow grave as a focus. A lockdown, an inverted circle of warding, keeping the spirits contained. If all fails, they would both share the body, locked forever in that shallow grave.
He turns his attention inwards now, towards the guest trapped inside his flesh and mind. With will made manifest, using his dreams as an anvil, wielding the hammer of his zeal he pushed the spectre to a corner of his mind-cage, one containing the silvery soul-fragment. He hammered, with willpower and mental fortitude, the soul together, as a blacksmith, wielding spirit-matter instead of metal, reforging what was once broken. One hammering clang at a time, he binds the soul to a whole, it rages and rails and tears and shrieks under the blows until it has the power to resist no more. It melds, it reforms, it is made whole, and with last efforts of will, the shaman expels it. As a drowning man, emptying his lung of water, so is this spirit expelled in coughing fits from a body near-dead.

The spirit now made whole hoovers, looking over itself and the shaman in front. Bran pushed up, weakly, blood still forming a small puddle about him, his body too weak to resist the fully formed spectre. Should the apparition wish to take revenge, the shaman'd be entirely at it's mercy.
The spectre regards him for long moments as it slowly starts to fade away; passing from this world to the next. The shaman falls back into the grave, power enough to barely muster a regenerative spell. He would lay in this shallow grave and let the Earthmothers embrace come over him and reknit his flesh.
A soul split once, now reformed, a spirit passing beyond the veil, and a shaman defying death for another. It was a taxing day with weeks of preparation leading to it, but… it put a soul to rest the right way, as a whole and it was worth it all.