Strand of Arasta

Wondrous item, rare (requires attunement)

Price: 1,000-2,000 gp | low sentimentality

It’s said that Arasta’s webs stretch from the Underworld through the mortal world into Nyx itself. This small strand has touched divinity and carries echoes of it—under sunlight, it sparkles like stars in a night sky, and at night, a faint, black fog emanates from it. While you have this strand wrapped around your body, your attacks deal an extra 1d4 necrotic damage and you regain lost hit points equal to the necrotic damage you dealt. You have advantage on checks to grapple creatures.

Curse

This item is cursed if Arasta (MOoT) is alive. Attuning to it curses you until Arasta dies or you’re targeted by a remove curse spell or similar magic. As long as you remain cursed, you can’t discard the strand, which sticks to your body and seems to generate more strands the more you tug. Each night, you suffer nightmares about being caught in a massive web woven of thin, white hair. You feel the strand vibrate around your body as a massive, ominous body approaches. Each day, you feel compelled to move closer to Arasta, though you don’t know her exact location. The nightmares intensify if you try to escape her web, and you’re unable to take a long rest unless you are closer to Arasta than when you finished your last long rest.

Paid

Once a day, while you have this strand wrapped around your body, you can use an action to summon one Nyxborn giant spider (MM) to fight for you. You control the spider telepathically and it shares your initiative order. The spider persists until it dies or until dawn the next day, whichever occurs first.

Overpaid

With some practice you realize the strands can be used to extend your reach. While you have this strand wrapped around your body, you gain 5 feet to your reach when you attack with melee weapons, as well as when determining your reach for opportunity attacks with them. You must roll a d10 every time you use your additional 5 feet of reach, and if you roll a 1, you drop your weapon.

Source: The Gray Merchant of Asphodel