Irene has shown to be very knowledgeable, showcasing herself as a historian when revisiting a folktale of her birthplace, seemingly enjoying the counterbalance of a "wonderful story" of the two angels of Zonia. She's shown to have a humorous side to her, as seen when she wanted to see Juliet and Heine do battle, only to later say it was a joke. In regards to her underlings, she is very attached to them, even referencing them as her "children," coming to their defense after their battle against Mirajane Strauss, painfully torturing the latter as collateral for defeating them. Irene is extremely confident in her own power, wanting to take care of Acnologia by herself (even talking of humanity's greatest threat without any timidity in her words) nevertheless as her very own comrades, among them being August, noted that they could not defeat the Black Dragon without Fairy Heart at their disposal. Due to this, her confidence not only spreads within her, but to the might of her Empire, saying that she could put aside the Majesty's "war game" due to the task of handling Acnologia, stating Alvarez (with her Majesty at the helm) would be victorious regardless of the outcome.
|Fairy Tail character|
She also displays signs of being a cruel individual, such as when she questioned Toma E. Fiore's love for his daughter, Hisui, after personally transforming her into a mouse. When displeased at his caring words for his child, she makes a muted expression on her face before moving to attack them, showcasing her dislike for things not apropos to how she conceives it to be. When she started to torture Mirajane, she devilishly promised her that not only would she not have a swift death, but after it is all said and done, she would turn her into a a lump of rotting meat, showing more of her evil and brutal nature. When serious, she has shown to criticize and be honestly blunt to those even above her, such as the Emperor, for the latter treating the war as a game and also inviting naivety in his heart in regards to his former lover, wanting to be the one to correct him through it all. Besides all of this, she is very respectful and complimentary to those higher than her, still delivering high praise to the same Emperor who she claimed if he participated in the war against Ishgar that it would be over sooner after it began, while taking honor from the Black Dragon's compliments after engaging in battle with him, returning the favor by saying the rumors of his power don't do him any justice in person. However, she can be somewhat vain as well as silver-tongued, remembering that she is no longer known as the "Scarlet Angel," but the "Scarlet Despair," desiring something much cuter to be called.
Four hundred years ago, Irene was a kind individual, having undergone political marriage to protect her country and end disputes. She was a firm believer in human-Dragon coexistence, best exemplified by her relationship with the Dragon Belserion, confiding in him her sadness at the mere thought of Dragons eating and mistreating humans, and even creating Dragon Slayer Magic so as to help the coexistence faction win the war, all with his help, all up until his death at Acnologia's hands, which left Irene particularly distraught. She was also extremely maternal, halting her fetus' growth with Magic when she was imprisoned for undergoing dragonification, and sped up the process solely to protect her. During her several hundred years of being a Dragon, Irene became obsessed with returning to her human body, and eventually, after getting it back, becoming a true human again. This obsession turned into insanity and desperation, with her trying to enchant herself onto her yet-still-unborn fetus and failing, which ended with Irene abandoning her newborn infant in Rosemary Village. This marked Irene's complete departure from how she used to be, and from here, she ultimately became the vain, cold-hearted and cruel individual in the present.
The above account of events is later stated to be false by Irene: she could not bear the idea of doing any sort of harm to her smiling infant (whom she loved), and instead opted to leave her, quite gently, in the care of someone else. Irene merely contrived the facade that she heartlessly abandoned her daughter as a means of coping, for when she came face-to-face with Erza many years later (and had her at death's door), she ultimately opted for suicide, still unable to actualize the desire to kill her daughter.