Will he help me in either a) making auto Hydra more consistent or b) clearing some of the more obnoxious Sintranos stages? If the answer to both is no, then I have zero need for him. I literally barely touch arena - I do the bare minimum to stay in G5, and I consistently drop in Tag by not doing the weekly 10.
I think Ankora is a solid support toon on her own. I had no Magic Cleanser/Reviver, so going for her was an easy decision. As for the duo together, I think their value is almost exclusively going to be PVP, especially High Classic and Live Arena, assuming they live up to the billing as being a counter to Tarichka.
However, I have only 30 void shards, so I am in no danger of even attempting to get Narses even if I wanted to. In fact, I have never even been close to haivng 110 void shards. I typically pull voids only during 2X events or for 10X events for toons I really want.