Bluetracker
Tracks Blizzard employees across various accounts.
According to Brian Kibler (HS Streamer, WoW TCG Designer, MTG Hall of Famer), Riot worked on and then cancelled a League of Legends card game.
https://clips.twitch.tv/SleepyDignifiedTarsierKappaClaus
Prety interesting, I think something about this was talked about at one point but I don't remember anyone saying it was cancelled.
w4ndr
Given that I mostly played/casted duelyst in the early days, I can't comment on the current state of the game. I do remember it burning through my laptop battery in like 3 games tho