"The sword uses your attack roll and ability score modifier to damage rolls."
I would rule that it hits exactly as if you were welding it.
If you are a rogue then you can use your Dex instead of strength if it is a light weapon.
If it is too big for you, you get disadvantage.
As a DM, I would let you get it further enchanted (upgrading it to a Legendary or Artifact item) that now lets you use it with advantage regardless of your size.
You are already a faery, with a fly speed of 30. The sword says flies up to 30 ft a round. I would let it do that. No double movement/dash for it, it wants to attack. I would require you to use 5 ft of your movement to hop on OR off.
So you could do a double action, fly 30 + 30-10 = 50 ft, then as a bonus action activate it, hop on, fly another 30 ft = total 80 ft, hop off, and have the sword do a single attack against someone there.
Dancing weapons with the heavy property by small/tiny creatures would be able to make attacks utilizing their bonus action without disadvantage, so long as that attack is made using the dancing weapons bonus action features.
though the sword uses your statistics fir attack and damage rolls, the bonus action attacks granted by this weapon are made without the weapon being wielded.
I know small creatures have disadvantage with heavy weapons but with the dancing blade you are technically not welding it. What would happen?
"The sword uses your attack roll and ability score modifier to damage rolls."
I would rule that it hits exactly as if you were welding it.
If you are a rogue then you can use your Dex instead of strength if it is a light weapon.
If it is too big for you, you get disadvantage.
As a DM, I would let you get it further enchanted (upgrading it to a Legendary or Artifact item) that now lets you use it with advantage regardless of your size.
Can you ride the sword? Like a flying surf board?
You are already a faery, with a fly speed of 30. The sword says flies up to 30 ft a round. I would let it do that. No double movement/dash for it, it wants to attack. I would require you to use 5 ft of your movement to hop on OR off.
So you could do a double action, fly 30 + 30-10 = 50 ft, then as a bonus action activate it, hop on, fly another 30 ft = total 80 ft, hop off, and have the sword do a single attack against someone there.
But that would be my house rule.
What if I wasn't a fairy and I just flew on it. Like if I was a gnome or a rabbitfolk
Dancing weapons with the heavy property by small/tiny creatures would be able to make attacks utilizing their bonus action without disadvantage, so long as that attack is made using the dancing weapons bonus action features.
though the sword uses your statistics fir attack and damage rolls, the bonus action attacks granted by this weapon are made without the weapon being wielded.
This old Crawford reply supports this.
https://www.sageadvice.eu/if-a-rogue-has-a-rapier-dancing-sword-if-it-hits-an-enemy-can-it-do-sneak-attack/
this means no smites, sneak attack, or many other on hit effects that actually require you to be the trigger.