I'm still curious as to who killed Yasuo's master. I don't believe it was Riven because she doesn't seem to have any wind abilities. I was wondering if there were any concepts for this?
"Don't look at me! I have no idea. No one has any idea. Why even ask?" tiptoeing quietly away
Riven's Ult (the second activation of it) is called "Wind Slash". This is the ability that is commonly said to be the one that killed Yasuo's master. If it's not, then we have exactly zero evidence of any other person that could have done it.
Riven is a front line warrior, not an assassin. She's too busy leading her troop (or escaping death from Singed's chemical warfare)
Out of all champ concepts I have seen there is only one possibility: AO SHIN, who was intended as an ionian wind dragon, who was supposed to be released way in the past, but then they ran into unexpected problems and moved him into distant future.
Now, I think honestly they revealed him as a teaser because they THOUGHT that they could release him soon...
Also, theory time! An ancient dragon in Ionia, a land striving for balance and elightement. If Ao Shin is as powerful as the teaser would have made suspected, he can be considered the manifestation of some kind of natural force - so why would he kill the elder? Because elightement and balance(in the ionian sense) are not natural. Anarchy is. Ao Shin was to be seen in Spirit Guard's Udyrs comic including some demon apes, the same apes that were also seen in JINX MUSIC VIDEO. AND WHAT DOES JINX LOVE THE MOST? Yepp, spreading anarchy.
Ao Shin is somewhere in the background, following his own agenda... and I think the moment he gets released we're going to see TONS of ionia lore... if he's released... somewhen...
still hoping...
Plot twist:
uses wind to kill
The only thing we really know about Yasuo's master death is that he got killed by a wind technique, which is used in an Ionian martial art. While Riven practices a similiar art, which is much more crude and brutal (Giant sword and whatnot), it is very unlikely that she killed him as she is a front line fighter and Yasuo's master was killed in his secluded temple.
Well RIOT need to unleash more champions with "wind" for his/her skill's name, that way there's gonna be more culprit to accuse to(this whole "wind" thing is a stupid based for an accusation even though that is what the lore said). Well I think 
is the one who killed 
's master, will the real killer please stand up.
on the official lol website you can look who up who is friends with whom ad also who is enemy with whom and if you look at yasuo you can see that riven is his enemy so i guess its kinda selfexplenatory who killed his master :D
sadly it was riven. i wish not because its a great thing to go off of for a new champion but it is
