I'm still very curious as to who the totally reimagined character is

It doesn't sound like it is Shao as was initially guessed, as I can't see how just going back to being a general would lead to a radical re-imagining and he still appears like he's going to be a bad guy. Reiko and Sindel seem similar to their past selves. I would imagine any major revisions of Reptile and Ashrah would lead to a revolt, and Nitara is a vampire so there isn't much more of a departure you can make there until she is just a different character all together.

Havik seems the most likely. There is also the possibility it is the character(s) we don't know about yet, which is why we don't know about them. Who do you think it might be, and how do you see them reimagined?