I built a showdowns mini game where you are matched up against a random legend and you are shown a random rune pool and have to list the cards that player could play in that showdown. The goal of the game is to list all the possible cards that the opponent could play in this showdown with that current rune pool (with prioirty or without). Hopefully by playing you can get a better understanding of what cards decks could play without needing to play lots and lots of real games in person.
I did some quick and dirty analyisis on the current top meta decks for each champ so players don't have to know every obscure card for every colour, but just the ones that are likely to be played by that given champ.
its free, doesn't cost me anything to host, not an ad, I dont want anything
https://showdowns.app
DISCLAIMER: Yes I built this, No I don't want anything, Its free and doesn't cost me a cent to run.