One of the best game-based cartoons so far. I haven't played LoL or Dota, but the animation and art style remind me of the Dishonored series of games.
The steampunk tech depicted in the story is smartly designed, interesting and beautiful. There are rigid airships, high caliber guns, and traditional gear tech. Hextech introduces magic to the mix and the resulting setting is richly detailed, complex, and harsh. As an RPG pencil and paper player I would love to play in the setting.
The characters are developing nicely especially Vi and Powder/Jinx. The growing conflict between them may end up being the final climax of the story. Jayce is certainly turning out to be a diverse character as he ascends the hierarchy of Piltover. Silco is also turning out to be a complex character--easily more than the criminal he was made out to be at the story's start.