That clip is nuts, but as others pointed out good luck pulling that off in a battleground. Arenas are the only place where you can get things to line up that nice and cleanly. In larger group settings, people see me casting greater pyro, an spriest silences me and then I get turned inside out by a warrior, rogue, and demon hunter.
Even ignoring GPyro, my combusts constantly get stolen and dispelled and meteor’s so slow that unless I blow a nova, whoever I was trying to hit has longed moved on by the time it lands.