Do you guys think that the new series of hxh will show How the phantom troup killed the rest five of Injou ?

Probably. I hope they will since its an important part of the story, I mean the gory part shows how strong a member of Genei Ryodan can be.

What is Injou? That's not even in the Hunterpedia.

I don't think there is going to be a new series because the author /mangaka died .