I have to agree with the OP as well.
Things normally go like this:
T1 – Player A lands stun kick on player B. Player B can only guess where the next attack will come in from and aim in that direction.
T2 – Player A knows exactly where player B is gonna be standing so he can attempt for a second stun kick. If he lands it player B should be getting acquainted to the thought that he’s already lost the match.
T3 – Once more player A knows exactly where player B is gonna be standing and aim for a power strike. A hit here pretty much marks the end of the match. If the defending player somehow lived past this point s/he will be bordering death either way.
Stun kick can be countered but only IF:
a) Defending player has counter-strike equipped.
b) Defending player has enough EP to activate counter-strike.
c) Defending player wins the mini-game.
The fact that this skill deals 1.6x damage in addition to the aforementioned stun doesn’t really do much to help the matter either.
With that said – I don’t think much needs to be changed. In my opinion a cost of 6 EP doesn’t seem like an unreasonable amount given its effects. Viewing it in comparison to the Heavy slash skill, which only deals 1.5x damage and doesn’t stun it just seems off that these two attacks should share the same EP consumption.
That is all on my part. :)