This bow was once an ordinary Oathbow, but spending eons in the Abyss has corrupted her.

She is a CE longbow with the following traits: 13 int, 6 wis and 17 cha. She can speak, read and write Abyssal. She can hear and see up to 60 feet away from her. She tends to whisper. She is hot tempered but she is friendly at first, however she quickly becomes irritable if her quest for revenge is ignored. She knows the true names of many demons. Her ideal is glory, she is quick to anger with anyone who does not use her “properly”. She is out for revenge on the people who left her in the Abyss. Her flaw is that she is quick to anger. She wishes that she didn’t need a wielder but will tolerate anyone who shares her desire for revenge. She loves it when she kills demons and when they are forced to join her on her quest. She knows the location of any demon, sworn enemy of the wielder and of her personal enemy that is within 120 feet of her and is quick to point such creatures out to her wielder. 

When you nock an arrow on this bow, she whispers in Abyssal, "You shall pay" When you use this weapon to make a ranged attack, you can, as a command phrase, say, "Doom befall you." The target of your attack becomes your sworn enemy until it dies or until dawn seven days later. If they survive long enough to stop being your sworn enemy, you suffer two effects from bestow curse, chosen by the DM. You can have only one such sworn enemy at a time. When your sworn enemy dies, you can choose a new one after the next dawn. If you’re sworn enemy is still alive by dawn on the seventh day, you cannot choose a new sworn enemy until they die.

When your sworn enemy is killed by you, the bow says “Vengeance has been achieved.” in Abyssal. When you sworn enemy dies in another way, the bow says “Disappointing.” in Abyssal. If your sworn enemy stops being your sworn enemy without dying, the bow says “You have failed me, now you must suffer.” in Abyssal.

When you make a ranged attack roll with this weapon against your sworn enemy, you have advantage on the roll. In addition, your target gains no benefit from cover, other than total cover, and you suffer no disadvantage due to long range. If the attack hits, your sworn enemy takes an extra 3d6 piercing damage.

While your sworn enemy lives, you have disadvantage on attack rolls with all other weapons.

While your sworn enemy lives, they suffer one effect from bestow curse, that you choose when they become your sworn enemy.

You may cast planar binding at 9th level on a demon once per year as an action. The spell save dc of this effect is equal to 8 plus your proficiency bonus, your charisma modifier and Valkyrie’s charisma modifier. Valkyrie controls the demon’s actions.

When you hit a demon with an attack from this bow, they take an additional 1d6 piercing damage, this damage increases to 2d6 if Valkyrie knows their true name. This feature doesn’t require attunement.

When you attack someone responsible for her stay in the Abyss, you gain a +2 bonus on attack and damage rolls against that creature. This feature doesn’t require attunement.

Proficiency with a Longbow allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Damage: Piercing, Damage: Piercing, Damage: Piercing, Damage: Piercing, Bonus: Ranged Weapon Attacks, creature proficient in longbows, Damage, Combat, Cursed, Bane, Sentient, Ammunition, Heavy, Range, Two-Handed, Slow