Dirgeblade

Weapon (rapier), legendary (requires attunement by a bard)

This weapon is an exquisitely crafted rapier set in a silver and leather scabbard. The blade glows a faint stormy blue and is encircled by swirling wisps of clouds. You gain a +3 bonus to attack and damage rolls made with this magic weapon.

This weapon, when unsheathed, sheds dim blue light in a 20-foot radius. When you hit a creature with it, you can expend 1 Bardic Inspiration to impart a sense of overwhelming grief in the target. A creature affected by this grief must succeed on a DC 15 Wisdom saving throw or fall prone and become incapacitated by sadness until the end of its next turn.

Once a month under an open sky, you can use a bonus action to speak this magic sword’s command word and cause the sword to sing a sad dirge. This dirge conjures heavy rain (or snow in freezing temperatures) in the region for 2d6 hours. The precipitation falls in an X-mile radius around you, where X is equal to your level.