New floating point move system and real time mechanics.
To fix that issue we have faced two problems. Mu server uses timers to calculate every game action. Usually its one second timer. It's like ping 1000ms. Our server has implemented one real time loop per map. It calculates move speed, skills collision and attack requests from game client.
Another problem was integer position. In mu online you can stay only on center of a square. Our client uses floating point position and optimized path finding. You can stay anywhere you want and choose unlimited paths to reach your destination.
With our solutions PvP fights depend only on your skill. There is no place for luck or server bugs.