Kai'Sa's been out for over a year now and Kassadin hasn't received a single audio update since. He doesn't recognize her. He doesn't interact with her. This isn't even some lore amnesia; this is developmental negligence. Which makes no sense because when Lissandra released, Ashe received a voice line or two immediately regarding their war, and last month received a full voice update. Kassadin found a whole daughter and nothing. If this new champion is Senna, don't neglect Lucian as well. His wife is back from the dead or whatever. Give him some lines alongside her release.
If it's true, of course. Regardless, Kassadin needs lines too.