Simply put, Wrathion is quite the Black Prince. Though he does not harbor the uncontrollable paranoia, insanity, and mistrust that the rest of his flight fell victim to, Wrathion does suffer from extreme vanity. He is a black dragon, and also supposedly the last of his kind, and he's not about to let you forget it. That said, he is rarely outwardly antagonistic without reason, and will only put you in your place if he feels you need it. He is petulant and very much works in the name of Azeroth, with little care for who he has to step on in order to ensure her safety. Even still, would much rather have champions of Azeroth do his dirty work than sully his claws.

Being a black dragon, Wrathion loves his heritage as a convenience only. He is constantly ashamed by his father's deeds and holds no love for the members of his flight. In fact, he had every last one of them murdered to ensure that Deathwing's corruption would halt and that his vision for Azeroth would be realized. Its important to note that Wrathion is an excellent liar, and that most likely 90% of what he tells you is a big fat lie. He knows that the color of his scales often instills fear, and he uses it to his advantage. It is implied that he's not entirely sorry for the loss of life during the Cataclysm, but mostly for Azeroth's pain as a planet. He is all for pitting the Alliance and Horde against one another to try and unite everyone under a single banner so that everyone might march against the looming threat of the Burning Legion. The plan ultimately fails, but he tried. Oh god did he try.

Wrathion is most certainly a dragon who holds grudges. He constantly reminds his "champion" (aka, the player's character) that despite the fact that the Red Dragonflight is the reason his mind is free from Deathwing's, he believes them to be his enemies because they had chosen to experiment on his egg in the first place. In addition to his grudges, he is prone to align himself with beings of great power, as shown by his initial kinship to Garrosh Hellscream. However, in the same vein, he is also wise to know that power is not everything. When Garrosh begins to lose popular support, he bets on Varian in hopes that he will overthrow the Horde and end the war between the two factions, keeping all focus on the doom he feels coming to Azeroth.

Though Wrathion is a dragon and he often puts on airs of superiority and maturity, the fact of the matter is that he is still something of a brat. He is often unable to consider viewpoints that aren't his own without great exposition and he is prone to losing his temper when things don't go his way. As Wrathion sees himself as the last line of defense for Azeroth, he has insane reserves of calm available for stressful situations (in spite of his tendency to tantrum when things do not go his way). It is rare that Wrathion will panic in the heat of battle, and there is little outside of his own personal demons that will cause him to flinch. It is this trait, as well as the appearance of infinite knowledge and wisdom (things that he doesn't actually possess, but often gives the illusion that he does), that make it easy to mistake Wrathion for being much older than he actually is. He's a calculated thinker, and he approaches almost everyone he meets and assesses their talents for ways they might be useful to him.

All of that said, age, failure, and hardship have recently done him some favors in the maturity department. On his quest to purge the corruption of Azeroth once and for all, Wrathion finds himself facing all of his previous mistakes, and grows to realize that he must become more deeply and personally involved in the war for Azeroth if he has any hope to save it. Along this journey, he keeps a journal, writing down his findings and drawing correlations in history and observing the frightening nature in which it seeks to repeat itself. He comes to understand why his entire dragonflight fell victim to Old God corruption, and why he is especially susceptible, and he vows to put an end to the cycle of hatred.

Ultimately, Wrathion's intentions are good. He is not powerhungry, nor does he willfully stomp on those he considers 'lesser' simply because he believes himself to be better. His arrogance is not a tool for destruction, it is simply a very annoying personality flaw. However, should one get in the way of his quest to save his planet, he will do literally anything to dispose of the problem. If that means killing thousands of people to save Azeroth, he will do it. If it means damning his closest friend to ensure Azeroth's survival, he will do it. There is absolutely nothing that will inhibit him from doing what needs to be done, if he believes it will further his cause.