Lance Guilliman belongs to a sacred order of knights whose oath upholds the ideals of chivalry, serving more as protectors and defenders rather than offensive might. Because of this idealism, their numbers are few, but they command a great deal of respect in the Kingdom of Stern.
Lance's conduct is considered exemplary amongst the Order and if he has any weakness at all, it's being unable to say "no" to anyone in need, even if it puts a great burden upon him.
Then there's Zarum, whose temper is only rivaled by his power. When Tolkien wrote the warning that states, "Do not meddle in the affairs of wizards, for they are subtle and quick to anger," he might have been referring to the Istari, but this is advice that those who encounter Zarum ought to heed, for when Zarum gets angry, the only things left in his wake are death, destruction, and suffering.