As people have previously said, kage is great because even the commons can have use. Also its really hard to say any of the rares are bad per se.

With Sage treasure, Ao is a common in Kage (you will rage if you get this) and orochimaru has been nerfed and lost some usefulness - and he was only really good in ranked anyways. You have roughly the same chance to get one of those as you do sage.

It took me roughly 170 pulls to get him. He has appeared in events before so you c*ways get fragments that way over time. Just save yourself a headache and do Kage.