It's called League of Legends (lol for short).
Its created by players from Warcraft 3: Frozen throne. Blizzard decided to ban a custom game the creator of Lol made on Frozen throne called Dota so he decided to make his own and took about a majority of the warcraft 3 players with him.
Its basically a pvp game of playing matches in teams of 5. You dont get to make your own character but they make new heroes every month.
http://www.leagueoflegends.com/What you can customize the bonuses that your hero gets as soon as he enters the game.
Prp and I play and Tobi plays here and there but he usually backseat plays.
Best characters for me:
Evelynn- stealth and magic bomb
Ashe- Ice archer
Soraka- Heal and support
Oh yeah and to get all the heroes you have to play the game alot, other than that they switch them out after a week.