Greetings fellow adventurers! Today I come seeking your opinions on a magic weapon I've been putting together for my game. Mostly in terms of whether or not it's over/underpowered for a 5th level character, if the Rarity value matches up, and if the theming makes sense.

Name: Winter's Waltz

Weapon type: Sabre (1d8 slashing)(Magical)(Finesse)

Rarity: Rare

Flavor:

Said to have once been wielded by a high-ranking noble of the Unseelie Court, whose grace and daring on the battlefield was matched only by his rakish footwork on the floor of Queen Mab's ballroom. This frost-coated cavalry sabre hums with the echoes of many of Winter's most moving symphonies, gifting its wielder with the ability to flit between enemies as if they were partners at a dance.

Stats:

+1 sabre (1d8 slashing +1d4 cold)(finesse).

Free Action: 1/LR Speak the command word Valiea ("let us dance" in sylvan).

Valiea: For 1 minute, Winter's Waltz softly sings one of the many symphonies its original owner danced to while in service to the Queen of Air and Darkness. During this time, this sabre's wielder can take the Disengage action as a Bonus Action.

Thanks in advance for your advice and input, and may the chests you find be forever full of loot, and bereft of tongues and teeth.

1. Clarify that this is a rapier variant, as officially I do not think anyone is proficient with 'sabre', despite it obviously being a re-branded rapier.  Otherwise no one technically gets the proficiency bonus to hit
2. Describe what happens if someone casts a Silence spell after the command word has been spoken.  Can you still Disengage?
3.  Did you mean that the weapon is +1 to hit only and damage is +1d8 slash + 1d4 cold, or did you mean damage is 1d8+1 +strength slashing, +1d4 cold.

Hey, thanks for the input!

1. I should probably classify it as a martial finesse weapon. Essentially a rapier but deals slashing damage instead of piercing. That way they'll know if they're proficient with martial weapons they can use their proficiency bonus.

2. I actually kind of like the idea of a silence spell keeping the wielder from disengaging, since they're no longer in the kind of... rhythmic zone, as it were, granted by the sword's song. But maybe if they step out of the AoE of silence, or if the silence is dispelled, they can disengage again.

3. The weapon itself is +1, so to hit rolls and slashing get the bonus, not the d4. How should I denote that?

Thanks again for the advice, and I hope you're staying safe out there!

Quote from M4flyer >>

Hey, thanks for the input!

1. I should probably classify it as a martial finesse weapon. Essentially a rapier but deals slashing damage instead of piercing. That way they'll know if they're proficient with martial weapons they can use their proficiency bonus.

2. I actually kind of like the idea of a silence spell keeping the wielder from disengaging, since they're no longer in the kind of... rhythmic zone, as it were, granted by the sword's song. But maybe if they step out of the AoE of silence, or if the silence is dispelled, they can disengage again.

3. The weapon itself is +1, so to hit rolls and slashing get the bonus, not the d4. How should I denote that?

Thanks again for the advice, and I hope you're staying safe out there!

 Like this:

Winter's Waltz

Weapon (Saber), Rare (requires attunement)

This frost-coated cavalry sabre is said to have once belonged to a high-ranking noble of the Unseelie Court. A personal advisor to the Queen of Air and Darkness herself, their grace and daring on the battlefield were supposedly only matched by their rakish footwork on the floor of Queen Mab's ballroom. This sword hums with the echoes of countless battles, and the sweet sounds of Winter's most moving symphonies. Those harmonious rhythms combine to grant its wielder with the grace to flit as easily between enemies on the battlefield as between partners at a dance.

A Saber is a Martial melee weapon, it deals 1d8 slashing damage on a hit, and has the Finesse property. If you are proficient with scimitars or rapiers, you are proficient with Winter’s Waltz.

You have a +1 bonus to attack and damage rolls made with this magic weapon. When you hit with an attack using this magic sword, the target takes an extra 1d4 cold damage.

Valiea. As a free action you can speak this magic sword's command word, for the next minute it softly sings one of the Winter Court’s many symphonies. As a free action you can repeat this sword’s command word to end its song. While you are holding this sword and can hear it sing, you can take the Disengage action as a bonus action on each of your turns. This property can't be used again until the next dusk.

 I figured that Dusk would be a better refresh for this weapon’s special property than a boring long rest, so I took the liberty. I hope you don’t mind.

PS- Those Kinda of command word properties are usuallly activated on a bonus action, not a free action.