891723 Kai is a polybag released on March 29, 2017. It contains Kai along with a golden katana and a golden chainsaw with fire at the bottom of it. It was included in issue 23 of the Ninjago Magazine.
Designer's notes
"I made all of the Ninjago magazine builds for 2017! We chose these figures to give kids another way to get the classic Ninja costumes, but I also wanted to include a fun weapon build that was reminiscent of their original Golden Weapons. Kai has a Fire chainsword, mostly because Gold chainsaw pieces are great."[1]
Trivia
- In this set, Kai comes with an incorrect double-pauldron golden armor and not his single-pauldron dark brown Honor robe armor.