Nice premise, with a few good scenes here and there but overall hot garbage.
Trashy but not quite abysmal and entertaining in the process on how bad this is.
Acting is generally awful, really awful for the main cast. The writing nonsensical.
Ocassionally random throwbacks, interrupting the flow of the story, confusing you as it's not immediately clear that you're seeing the past. Nor _why_ you see the past. Until episode 8 where someone on the show thought, hey let's do it 24 style but more confusing and give information that we go back x hours now.
Several scenes are dragged out for way too long for no apparent reason other than perhaps filling screentime.
Dialogue? Usually very sterile and/or pointless. CGI? Oh, boy. One of the worst I have ever seen.
The knife in the guy's hand in the first episode is only the tip of the iceberg.
Music choice is almost always entirely out of place (and loud), fighting sounds at the beginning over the top and ridicolous.
The latter tones down as the show's ongoing but still way too loud and obnoxious.

Kai has never any clue what he is doing, he is just _thrown into_ situations. This "works" because he (almost) never tells anything on why he is doing something or plans to do. Kai is a hollow, spineless (until he is suddenly not for no reason) and dumb character. There's no logical growth in his character (in S1 at least).
Iko Uwais is way out of his league in this. He is terrible and miscast for this role. Not that his character demands much and the writing is all over the place, not helping him in any way. But his character is an a-hole just to be an a-hole to begin with. Unlikable and unrelatable.

Speaking of unrelateable, Lu Xin, because he got burned by Uncle Six as a kid (accidentally we can presume) he sees himself as a "monster". That whole revenge subplot seems like the writers didn't know how to tie up loose ends when Uncle Six revealed his powers and who was really responsible for his (Lu Xin) burns.

The female characters in this are badass and the best part, though. Without making any social commentary.
Except for Zan, her story is way too much on the nose, predictable and quite boring. Choreographies are hit and miss, which is suprising to be honest given the action oriented nature of this show. Tommy's good, too, he's growing on me. Lawrence Kao is probably the only main character giving actual character to his role. Kevin Durand as a side character only appearing shortly to be killed off immediately. Damn, Durand is great. He outshines Uwais by so damn much in just a few scenes, it's hilarious.

This series feels like a sandbox for newcomers to showbiz. Netflix might have put together whoever was available to write something up and make a series. There's no clear structure in this, ideas over ideas scattered around. No clear direction whatsoever. Too bad since the premise isn't that terrible.