Hello all! I'd like to ask, what rarity would you consider this custom weapon?

Moonlight Stinger
(Requires Attunement)

You gain a +1 bonus to attack rolls and damage rolls with this rapier.

This weapon has 3 charges and regains 1d3 charges at midnight.

As an action you can spend a charge and move up to 30 feet in a straight line, passing through spaces occupied by creatures without provoking opportunity attacks.

Each creature of your choice that you pass through must make a Dexterity saving throw (DC 8 + your proficiency bonus + your strength or dexterity modifier) or take piercing damage equal to 1d8 + 1 + your strength or dexterity modifier.

Rare probably, because a normal +1 rapier is an uncommon magic item, and this weapon has a +1 while also having an additional useful effect. 

Quote from Zalakhiel >>

Hello all! I'd like to ask, what rarity would you consider this custom weapon?

Moonlight Stinger
(Requires Attunement)

You gain a +1 bonus to attack rolls and damage rolls with this rapier.

This weapon has 3 charges and regains 1d3 charges at midnight.

As an action you can spend a charge and move up to 30 feet in a straight line, passing through spaces occupied by creatures without provoking opportunity attacks.

Each creature of your choice that you pass through must make a Dexterity saving throw (DC 8 + your proficiency bonus + your strength or dexterity modifier) or take piercing damage equal to 1d8 + 1 + your strength or dexterity modifier.

 I would think you should change it to "you travel up to your speed in a straight line, passing through spaces occupied by creatures without provoking opportunity attacks." This makes it so that slower characters cannot use it for a huge movement boost, and faster characters aren't impaired by it. That's just my two bits though.