Great data! I have a suggestion and a question.
Suggestion: In the summoner vs chart, both 100-0 records and no matchups are being reported with 0. It'd be useful if absent matchups were represented in a different way, such as with N/A, an X, a dash (-), or something.
Question: Have you considered adding a "default" representation to help distinguish data with small sample sizes from actual good/bad records? For example, in Bronze, both Phantom of the Abyss (11-0) and Frost Lion (1-0) have 100% win records, but it's clear one is strong while the other is sample size. One easy option is to initialize all cards with a 1-1 record. A more rigorous method might estimate error from sample size.
Anyway, thanks, and keep up the good work!