The main force of chaos in Dragonwood is Lord Maul who is seeking to control the interdimensional portal nexus so that he may use it as the base from which he launches his invasion of the multiverse. Lord Maul seeks wealth and power to ensure his legacy and his infamy and to conquer and control all of the realms of Dragonwood.
Lord Maul sees all uninvited travelers, both intentional and accidental, as threats to his control of his realms and to his larger plan to conquer the multiverse.
Lord Maul himself does not venture from his stronghold. He selects the strongest and most proficient of his minions, recruited from the peoples of his conquered worlds, to lay siege to and destroy any uninvited travelers. This wide-ranging and diverse army means that all adventurers planning to travel to Dragonwood cannot know what awaits them there until the assault begins.