Reading fandom-blind here since I've already reviewed everything of yours from fandoms I recognize...

Besides being entirely unfamiliar with the world in general (which is disorienting enough - so many unfamiliar terms x_x), I'm not sure I understand what was going on here. Shepard died and was brought back through bio-engineering, or something?

The relationship between the couple doesn't seem to be very romantic, although from what I can tell from this fic, Kai Leng seems like a permanently-angry person, so I suppose that his personality doesn't lend itself well to romance.

I didn't spot any typos or grammar issues.

That's an interesting idea!
Having Shepard and Kai Leng know each other from their past!
I really am looking forward to reading more.

I liked this. This is intriguing. It would be interesting to see their dynamic thru me2 and then me3