In kage treasure, there are 8 designated rare ninja - Chojuro, Bee, Mifune, Darui, Danzo, Gaara, Mei and Onoki.

Let's say I bought Darui from the monthly event rewards. Can I still get darui from treasure before having all 8 of them?

I'm assuming there wont be a duplicate rare before having all 8. Is this correct?

If any mod can clarify this, it will be really appreciated.