Magic Items

Ring of Mind Shielding
Ring, uncommon (requires attunement)
While wearing this ring, you are immune to magic that allows other creatures to read your thoughts, determine whether you are lying, know your alignment, or know your creature type. Creatures can telepathically communicate with you only if you allow it.

You can use an action to cause the ring to become invisible until you use another action to make it visible, until you remove the ring, or until you die.

If you die while wearing the ring, your soul enters it, unless it already houses a soul. You can remain in the ring or depart for the afterlife. As long as your soul is in the ring, you can telepathically communicate with any creature wearing it. A wearer can’t prevent this telepathic communication.

A small iron casket among the oni’s belongings holds a gift to the Lord of Oni—a trick box made out of eighteen plates of platinum, eighteen plates of electrum, and eighteen plates of silver. The box is opened by sliding certain plates on the left side, then the top, then the right side in a particular sequence. The correct order is platinum–electrum–silver on each end, and silver–electrum–platinum on the top.
The box has properties similar to those of a bag of holding—although the container is but 10 inches long by 6 inches wide and 4 inches deep, it holds 3 cubic feet of material or 60 pounds, whichever is the lesser. At present the box contains 500 gp, a potion of mind control (frost giant), and a potion of cloud giant strength

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.

Pipes of the Sewers
Wondrous item, uncommon (requires attunement)
You must be proficient with wind instruments to use these pipes. While you are attuned to the pipes, ordinary rats and giant rats are indifferent toward you and will not attack you unless you threaten or harm them.

The pipes have 3 charges. If you play the pipes as an action, you can use a bonus action to expend 1 to 3 charges, calling forth one swarm of rats (see the Monster Manual for statistics) with each expended charge, provided that enough rats are within half a mile of you to be called in this fashion (as determined by the DM). If there aren’t enough rats to form a swarm, the charge is wasted. Called swarms move toward the music by the shortest available route but aren’t under your control otherwise. The pipes regain 1d3 expended charges daily at dawn.

Whenever a swarm of rats that isn’t under another creature’s control comes within 30 feet of you while you are playing the pipes, you can make a Charisma check contested by the swarm’s Wisdom check. If you lose the contest, the swarm behaves as it normally would and can’t be swayed by the pipes’ music for the next 24 hours. If you win the contest, the swarm is swayed by the pipes’ music and becomes friendly to you and your companions for as long as you continue to play the pipes each round as an action. A friendly swarm obeys your commands. If you issue no commands to a friendly swarm, it defends itself but otherwise takes no actions. If a friendly swarm starts its turn and can’t hear the pipes’ music, your control over that swarm ends, and the swarm behaves as it normally would and can’t be swayed by the pipes’ music for the next 24 hours.

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.

Wondrous item, common
This fearsome steel helm makes your eyes glow red
while you wear it.