Was Kled present at the battle where Sion killed Jarvan the 1st?
Kled is old, really old by the looks of it (as Yordles can now be very old) so I'd imagine he and Sion at least knew of each other when Sion was still alive.
Now apparently Kled says, "I liked you better when you were alive." To possibly Sion, referencing some level of respect (as much as someone like Kled is capable of giving, which I imagine isn't much). So if this liking was towards Sion, was it on a professional basis or personal basis (I. E. Friends of some form)?
I'm interested to see what this old Vet can reveal about my main and favorite champion.