At the moment the move Killing Blow is the only move that is able to murder your opponent. On top of this it takes a small lifetime to actually execute the move. This is terrible for group kambert and here's why.
You're strolling around minding your own business one day when 3 red dots appear on your map.
You're feeling pretty ballsey and you decide to attempt a 3v1 and you've managed to KO one of your attackers.
The other 2 are still on your tail and since they still have a decent amount of blood there's no way for you to quickly dispatch of your first KO'd attacker before he is sent to his homestead.
In haven you hit straight through the persons defense bar if they're KO'd with any attack. This means you can circle back and get your revenge making your likely death due to the remaining gankers less harsh. Killingblow in its current state is far too slow and therefore it should be used as just a hard-hitting attack, not the only means of murder. Any attack should be able to murder your opponent to make group combat more rewarding for the underdog.
The reason why this was changed to begin with was because people were killing eachother accidentally while sparring.
In addition to this fix sparring should be implemented.