Laxus is a very big and strong wizard, in fact one of the strongest in the Fairy Tail Guild, He can be very intimidating, but deep down he cares so much for his guild mates.
As a result of his love and car for his guild mates he wanted nothing more than to make them stronger. However he went about making that want a reality with a method that would do more damage to his guildmates than anything else, even bringing some close to death. As a result, the guild master of Fairy Tail AKA his Grandpa has to make him confront his actions and eventually expel him from the guild.