Ekko and Zilean
Zilean is a chronomancer with near perfect control of time and a respect for it so immense he never uses his powers in such a way as to break time or cause something to undo itself except in extreme scenarios. He learned this the hard way.
Ekko is the opposite, he has a limited control over time, but uses it to undo things that would otherwise have killed him or someone else pretty much every time it happens, hell, it doesn't even need to be a death for him to break time.
So what do they think of each other?