instant kills are canon question mark?

Zato "I'd love to hear one of your lectures, but...now there's no time."
Slayer "So I'm being a nuisance, you say...?"
Zato "Indeed...senile old man...OUT OF MY WAY!"
(*Cue "Haven't you got Eyes in your Head?"*)
*Screetch/Crash*(Zato summons Eddie as it blasts through the room)
Zato "(Even now that old man's going easy on me...as expected...)"
Slayer "Your rushdown is weak. You should've prepared your Instant Kill technique, that shortcoming will cost you."
Zato "Ready my Instant Kill? The Leader of the Assassins needs only ask. Then I shall show you! PIERCE THROUGH!!"
(Zato launches his shadow forward as a giant hand trying to crush Slayer with "Fear of the Dark")
Slayer "Is this some kind of joke? Too slow!"
(Slayer dodges the attack and counters with his own punch)
Zato "Gwuugh--eughh!!..."
Slayer "One: In a life and death struggle it is expedient to never exceed one's own limits when performing an Instant-kill technique.
Two: A killing technique's intent must be refined to it's absolute potential within the craft to support one's boast of skill."
Zato "(That is...the Organization's Way...!)"
Slayer "Correct! And for that 'way' to happen something must occur: Real conflict follows rules, a life and death struggle's outcome is not decided by prideful intent. A man must thrive in conflict, a man who can stand alone and inspire those below him is unstoppable. As you are now, you are insufficient!"