Necrofeller

Weapon Heavy, Two-handed, Silvered Legendary (this item requires attunement) [Any melee-focused class can attune to this object, as long as their hearts are bent on destroying the Necrochanglings. Then the mind of the sword will align and attune to the user. ]

The sacred sword Necrofeller has the magical properties to dispel the Necrochanging Disease from people.However, this will only happen when the user is properly attuned to the weapon. The sword has a mind of its own, and lets the user attune to it depending how the sword judges its wielder. The more worthy the sword thinks its user is, the more powerful it becomes. Stage One, Meeting: When you hit a Necrochangling with the Necrofeller when it is in its Changling Form, you'll get +4 damage. Stage two, Acceptance: When you hit a Necrochangling with the Necrofeller when it is in its Changling Form, you'll get +4 damage and the Necrochangling must make a DC 10 Wisdom saving throw. If it fails the save, it reverts to its regular form and has to spend an action to change back. Also, as a bonus action, once per battle, the user can unleash a wave of Radiant light with the sword. It passes through every creature in its path, but only damages Necrochanglings. In a cone of 15 ft, every Necrochangling must make a Dexterity Saving throw. If it fails, the Necrochangling takes 1d8+the user's Wisdom modifier damage.