The Chosen Ones

Descriptions of difficulty levels mentions some huge rewards obtainable after ending campaing. what is that? is it possible to get it now, before ch 10? I'm asking, cuz i didn't saw any information at the end of ch8 video

I can confirm that there is no such reward at all at the moment. If you complete ch 8 you get nothing, the best option is to sell everything and give up at least then you have resources for your next playthrough.