Kartana

This Ultra Beast came from the Ultra Wormhole. It seems not to attack enemies on its own, but its sharp body is a dangerous weapon in itself. It was observed cutting down a gigantic steel tower with one stroke of its blade.

Appearances
First appearance: Pokemon Sun & Moon (2016)

Information
This Ultra Beasts earlier on in the games is called ???, as well as UB-04 Blade/Slash.

Kartana is the version exclusive UB-04 for Sun, The one for Moon being Celesteela.

Kartana, As of writing this article, has no description on the pokemon sun and moon website.