Errata, Warlock quick build – Ray of Sickness is not a Warlock spell

Does Dispel Magic stop the Storm of Vengeance from affecting everyone?

Great Weapon Master feat, can I take the bonus attack on crit?

Hi guys, if I have the Great Weapon Master feat, can I take the bonus atk on crit or kill with one hander?

I am trying to develop a playable ogrillon race. Any suggestions?