Guarding

A successfully guard on a skill is called counter attack,which it has not implement in game yet.
(guard skill by default is key ''R'' and it suppose to counter attack KD's (knockdown),its not a great measure on pvp and most players dont complain about it,because most of them didnt use it or never upgraded it,it is was always a bit of useless cause it works on timing your guard at the second you are about to get KD).

Another way to counter skill attacks is resistance,but as far as i know it aint working properly atm,might be wrong tho and hope other people can help you out with this cheers.