Above is a screenshot of a minetest character wielding an air sword.
You can confirm that it is a genuine air sword because it is invisible. If you could see anything in the characters hand, that would prove this picture to be a fake.
And below is a screenshot of a minetest character battling a wolf mob with the air sword
You will notice the sword in the hand is invisible, AND the inventory image is also invisible. Both proof positive that the character is wielding the air sword.
Here is a screen shot of a minetest character wielding an air sword against a treeent mob:
Again notice the tell tail signs of the air sword: Invisible sword in the wielding hand and invisible icon in the active inventory slot.
And below is a very interesting screen shot of two minetest characters dueling with air swords!
You'll notice how both the pov character and the one in the view are battling with invisible swords in their hands. Air sword battle.
Do you need me to take any more screen shots of the air sword to convince you? I can do this all day.