I'm assuming that for Unalaq there is also no Dark Avatar State.

We've literally never even seen Senna waterbend. We only know that she is a waterbender through supplemental material.

I know, I just felt the need to fill up all 6 poll options :P

I don’t even think that Senna is even a water bender at all.

Really, well that’s a good thing to know.😁

Korra since she s the avatar and has Been training since 4 years old and I mean she was holding off Deana and eska pretty well until the dark spirit showed up and she beat unnalaq at his own game before he cheated and fused with vaatu