Gragas or...
Camille E
Tie
Reborn
Spirit Abjuration
Aurora
Gangplank Q
Yes
Master Yi and Wukong
Yes, wukong was yi's student
Warwick R
Warwick
Kai'sa: "Are you the _? or the _?"
Hunter/Prey
Searing Brilliance
Mel
Yes, however it does no bonus damage
Ryze and Nasus
Met in the "Call of Power" cinematic
Pantheon W
Gragas
Aatrox: "Now, hear the silence of _"
Annihilation
Trial by Fire
Gangplank
Nasus Q
No, base auto damage crits but q does not
Vayne and Graves
Met during the events of the ruination
Illaoi W
Gragas
Zaahen: "Fight against the _"
Fall
Determination
Xin Zhao
Lucian R
No, shoots more bullets with crit
Fiddlesticks and Tahm Kench
No
Garen Q
tie
Fizz: "_"
lemmeattem
Dirty Fighting
Akshan
Smolder Q
No, damage increases but no crit
Rengar and Milio
No, however Milio calls Rengar "big dagger cat"