This player is (doubtlessly) one of the biggest scumbags of kdice currently.

He has annoyed dozens of players recently (me included), because he keeps doing the same thing over and over.

Unfortunately, lying is allowed within the current rules of kdice and so are akca03's actions.
If the mods interpret the kdice rules strictly, there is no way for them to ban him.

Nevertheless, I do hope that one of them will also consider the advantages of a ban of akaca03 (i.e. less frustrated players and more faith in "kdice justice")...
...and eventually will ban him.

I am sorry but there are no rules against lieing or backstabbing, or taking back a flag or ignoring a flag or against refusing to flag out, or against suiciding on someone and then flag out, etc etc.

Those are all bad habbits but impossbile to ban for, even if it happens over and over. That's why we have reviews. I know this is far from a waterproof system, almost nobody reads reviews while playing a game with people they don't know. But it's all you can do: leave bad reviews and hope people learn about annoying players in time from your reviews.

you are now warned too, you will only be fooled by this guy once (I hope). In fact, it's all part of becoming successful at this game: learn to screen your opponents, remember who are the bad guys, learn how to make people flag in time (demand real flags) so they can't revolt or backstabas easy, learn how to spot potential jerk moves from the first signs in a game, etc.

The idea has been raised and discussed before. We should have more than just the review system. A rating system for after each game would be nice. You could rate your opponents on fairness and people will get a fairness counter next to their avatar. Someone with very bad ratings will get a red button or something else next to their name. Fair and friendly people will have a green button. So when people sit, you can judge their style a bit in advance, based on the rating button.