Never heard of Mixer nor Ninja, but I have heard of Twitch. I'm not dead yet! I can still understand 1/3rd of the nonsense people care about nowadays. Oh wait I've heard of Fortnight as well, 2 out of 4!! I'm doing well.
Was literally thinking the same thing, my thought on reading the thread title was "I understand one of those three nouns" I was taking a shot in the dark that it wasn't referring to an actual Ninja.
Why not check me out on youtube and help me on the way to 2k subs over at www.youtube.com/stormcloudlive