1. Respect your opponent: Doesn't matter which character your opponent chose don't be an ahole. Every character can be defeated some can be defeated harder than oders.
2. Don't rage quit after the first round: If you lose the first round don't quit. Try different tactics, your opponent defeated your first round tactic so you need to create another one. Because your enemy has to change his tactis too.
3. Have honor: If you win or lose have honor. Your opponent was better respect that and try to learn from him. If you win, don't brag about it. Your opponent tried to defeat you but failed, respect the effort. And at the and of the match thank him the match. Say gg or good fight
4. Don't cheat: Don't use the exploits if your opponent doesn't using them it is just unfair. Don't be a turtley guy. Don't just defend and relie on parry. Attack, fight be agressive. You can look for parries, just don't be a turtle guy.

I just feel that so many players take this game too seriously. This game is not ready for competitive level it is just for fun. Until they balance the characters, fix the connectivity, get rid of the bugs/exploits and fix the turtle meta, this game is just an "investment", not a serious game.

I just felt that I have to say this after many people i have faced against in duel rage quited or said "Vortexing b*tch", "light attack spaming PK" or "Sweep spaming ahole". Just relax and play this game for fun.