Information and the Carousel Phases
The carousel phases are problematic. At all other points in the game, you can hover or click to look up champion stats, abilities, affinity, etc. and item effects. But in the carousel, none of this information is available. Sometimes it's even hard to tell which champion is which (for example I have confused Pyke and Twisted Fate a few times), and the item icons are not exactly huge either and can be difficult to see.
The issue this causes is that suddenly, and unlike in the rest of the game, you have to have memorized everything about champions and items so you can identify what you need on sight. At a minimum, that is name, class and affiliation (so you can get sets if you need them) for champions and every single item icon and it's effect. And you have to do this in a rush, as you are racing other players to the best pick for your build, and the clock, which prevents you from looking much up. This is already a lot to have in your head (especially when the information isn't needed anywhere else), but as the game expands and receives at least new champions, keeping track of all this information is going to get harder and harder.
This phase needs to be redesigned so the information available to the players is on par with that in the rest of the game. You should never lose because you grabbed the wrong champion or item you couldn't identify them visually from memory in a rush. It makes the game less tactics and more memorization for no reason.
I realize you are going for a theme here, and this is the only part of the game where the little legends actually serve a purpose (picking up items with them is busy work and should be replaced with automatic pickup), but the current way it works is just too different from how the rest of the game functions and leaves too much to memory.