Magic Items

Hell Hound Cloak
Wondrous item, rare (requires attunement)
This dark cloak is made of cured hell hound hide. As an action, you can command the cloak to transform you into a hell hound for up to 1 hour. The transformation otherwise functions as the polymorph spell, but you can use a bonus action to revert to your normal form.

Sword of Vengeance
Weapon (any sword), uncommon (requires attunement)
You gain a +1 bonus to attack and damage rolls made with this magic weapon.

Curse. This sword is cursed and possessed by a vengeful spirit. Becoming attuned to it extends the curse to you. As long as you remain cursed, you are unwilling to part with the sword, keeping it on your person at all times. While attuned to this weapon, you have disadvantage on attack rolls made with weapons other than this one.

In addition, while the sword is on your person, you must succeed on a DC 15 Wisdom saving throw whenever you take damage in combat. On a failed save, you must attack the creature that damaged you until you drop to 0 hit points or it does, or until you can’t reach the creature to make a melee attack against it.

You can break the curse in the usual ways. Alternatively, casting banishment on the sword forces the vengeful spirit to leave it. The sword then becomes a +1 weapon with no other properties.

Javelin of Lightning
Weapon (javelin), uncommon
This javelin is a magic weapon. When you hurl it and speak its command word, it transforms into a bolt of lightning, forming a line 5 feet wide that extends out from you to a target within 120 feet. Each creature in the line excluding you and the target must make a DC 13 Dexterity saving throw, taking 4d6 lightning damage on a failed save, and half as much damage on a successful one. The lightning bolt turns back into a javelin when it reaches the target. Make a ranged weapon attack against the target. On a hit, the target takes damage from the javelin plus 4d6 lightning damage.

The javelin’s property can’t be used again until the next dawn. In the meantime, the javelin can still be used as a magic weapon.