Masterpiece. I don't play LoL though I don't live in a video game vacuum so I am aware of it. Don't let that deter you any more than it would deter you from watching any movie without reading the book. I'm only on episode 4 and this animated series is a ****ing banger. Action, angst, dark, broody, intense, clever... beautiful, melodic, stunning.
I would subscribe to Netflix based on this show alone that's how engaged it got me. I left a review because I almost passed it up because I'm not a LoL guy, and that would have been a tragedy.