How do u guys think the combination of armament and observation haki and rokushiki techniques can be used ? So far we haven't seen anyone using this combination, not even Lucci, who was the member of CP9 pre-timeskip confirmed to have haki.

Imagine combinations like Tekkai and Armament Haki, or Kami-e and observation haki

And which other character do u guys expect to use this combination ? Besides Who's Who, that we already know