Magic Items

Symbol of Power. This item was once used as part of royal regalia or as a badge of high office. Its former owner or that person’s descendants might desire it, or someone might mistakenly assume its new owner is the item’s legitimate inheritor.
minor property: Key. The item is used to unlock a container, chamber, vault, or other entryway... though which one is unknown.
quirk. Metamorphic. The item periodically and randomly alters its appearance in slight ways. The bearer has no control over these minor alterations, which have no effect on the item’s use.

According to the previous owner, this was freed from the ownership of a trio of spirit naga. Much better in my hands than their... tails? sure.

The harp is made out of white bone, carved to look like a kraken with its tentacles ending in the strings. The sounds it produces is especially well-suited for dirges and sea shanties. It glows when a celestial approaches within 100 feet of the harp.

Wondrous Item, very rare (requires attunement by a bard)
This beautiful harp is an exquisite example of its kind, superior to an ordinary instrument in every way. A creature that attempts to play the instrument without being attuned to it must succeed on a DC 15 Wisdom saving throw or take 2d4 psychic damage.
You can use an action to play the instrument and cast one of its spells. Once the instrument has been used to cast a spell, it can't be used to cast that spell again until the next dawn. The spells use your spellcasting ability and spell save DC.
When you use the instrument to cast a spell that causes targets to become charmed on a failed save, the targets have disadvantage on the saving throw. This effect applies whether you are using the instrument as the source of the spell or as a spellcasting focus.
This instrument can cast the spells fly, invisibility, protection from evil and good, control weather, cure wounds (5th level), and wall of thorns.

This alabaster lance, named "Dream Whirl" by those who created it, is carved with deep swirling patterns that seem to move with you, calming your emotions and silencing surface thoughts.
Also, the original owner's dreams and anger still dwell within the lance. When within 120 feet of an illithid (mind flayer), its kin, or any of its creations, righteous fury radiates from the lance as it darkens into deep blood crimson.
Otherwise it functions as a +3 lance. This item can be found in the Dungeon Master’s Guide.

The hilt of this weapon is covered with carved, ancient Rellanic runes that seem to comprise nonsensical words or, possibly, a list of proper names.

You gain a +2 bonus to attack and damage rolls made with this magic weapon. The sword has 9 charges. If you score a critical hit against a creature that has fewer than 100 hit points, it must succeed on a DC 15 Constitution saving throw or be slain instantly as the sword tears its life force from its body (a construct or an undead is immune). The sword loses 1 charge if the creature is also slain. When the sword has no charges remaining, it loses this property. This item can be found in the Dungeon Master’s Guide.