As pointed in a separate thread, slowness arrows can prevent you from strafing or saving yourself from getting knocked into the void. This can absolutely ruin EggWars Duels, as you only need to shoot your opponent once and it's pretty much a free kill.
As for weakness arrows, if you shoot a player once during combat, they do barely any damage and you also get a free kill.
As for weakness arrows, if you shoot a player once during combat, they do barely any damage and you also get a free kill.