This magical ball of yarn can be used to tie the lives of people like it's done in devilish pacts.

It's seven infernal leagues-long and grows 1d4 of them back every day at midnight.

Blood Knot. When you hit a creature with an attack you can use a bonus action to burn two of the yarn's leagues to form a blood tie between them and another creature you can see within 30ft. The second creature must make a DC14 Constitution saving throw or suffer half as much damage as the first.

War Knot. You can tie up to seven of the yarn's leagues around a willing creature's limb so they receive half the damage suffered by you in your stead. Each league shares the damage of one instance of damage suffered by you - an attack, a spell, an effect, falling etc.

The knots can be removed with a bonus action and more than one can be removed at a time, ending the effect of the removed ones. The league of yarn used on the knot burns up when removed or when damage is shared by it.

(All credit goes to @Shiny_Press on Twitter, ShinyPress on Instagram and Shinypress on Patreon! I just recreated the item for D&D Beyond consumers, and will remove it if requested.)

Notes: Negation, Utility, Combat