I've heard of people getting Rasa/Gengetsu twice, but only once. I've noticed a pattern on how the treasure works.

So basically, in the future, it's supposed to split up into 2 treasures, 1 with Rasa, Ginkaku, and Kinkaku. The other with Gengetsu, Kabuto, and Mu. I've seen a pattern with the super rares. Basically, If you get more Ginkaku/Kinkaku then Mu and Kabuto, it'll be Rasa, works vice versa, more Kabuto/Mu then Ginkaku and Kinkaku, it'll be Gengetsu.

Atleast that's what I've gathered. I'm also going for Gengetsu because I literally have nothing else to do, already got Roshi, already got 7 kage rares (7th recently, was my first dupe one.), and might save for gnw after this...or just go for Jin 2