Aleister is a tall man. He has blue eyes, short, light blonde hair and pale skin. He wears a white shirt, purple tie and a blue striped white sweater.
Aleister is a portly, well-spoken gentleman, but appears to be very materialistic and irritable, to say the least. He sees his peers as lesser beings than himself. Aleister appears to be very intelligent, which makes him rather compatible with fellow group member Grace, who he was getting close to up until his paternity was revealed. Owing to his "daddy issues" Aleister also finds trouble trusting people, and tends to only speak up when he feels his input is helpful, which is essentially all the time. He was one of the top five fencers in England, and was valedictorian.
Aleister respects Grace for seeking knowledge. He is hinted to have romantic feelings for her, as he grows quite flustered when the two are interacting. He seems to care a lot about how she sees him and doesn't want her to get into trouble. They continue to get closer until Aleister's secret is revealed, and Grace loses some of her trust for him. When you choose to encourage Grace to go to him after this and shout at him to listen to her, they share a kiss. And later when you go to Grace's room, he is there too. If Grace is left behind in the final chapter, Aleister will express sadness towards her disappearance; if you rescue her, he'll appreciate it.
in Endless Summer book 2, Aleister is reunited with Grace (if you chose not to rescue her). When entering a secret place full of treasure, Aleister is hit by several darts containing a sedative that causes him to behave strangely. An example of this is when he supposedly hears music in his head and begins to waltz. He asks Grace to dance with him (you need diamonds for this) and in the end they share a kiss after Aleister confesses his feelings for her.
He originally states that Your Character, and many others, are idiots and simpletons. In Chapter 4, if he/she sprays the chain to the release valve with the gas from the fire extinguisher to brittle the metal, instead of bashing it,you will manage to impress him. He goes as far as to saythat Your Character isn't as dumb as he originally thought. In Chapter 13, when Your Character finds out that he is a Rourke International Asset, the college student can choose to call him a liar and that he/she doesn't trust him.
While this isn't revealed until Chapter 13, Aleister is Everett Rourke's son, and despite being named after him, Aleister feels nothing but contempt for his father. This is because Rourke had been absent for a large portion of Aleister's life. According to Aleister, on his 10th birthday and the day of his graduation from high school, Rourke was abroad on both occasions. In fact, the whole reason Aleister is on the island to begin with is because he wanted to confront his father and cut ties, but Rourke was under the impression that his son was looking to make amends.
Aleister dislikes Jake because he doesn't agree with Jake on many issues. An example of this is when Jake guesses that the Sabertooth is from the Jurassic Era, but Aleister becomes enraged that Jake was "only 140 million years off" and states that the sabertooth is fact from the Pleistocene Era.
In Book 2, Chapter 8, it is revealed that IRIS is the artificial intelligence of Aleister's deceased mother. Ever since, Aleister is shown to trust her and refuses to believe that she is leading them into a trap.
- Aleister is annoyed to discover that Your Character has a higher threat rating than him.
- His Hadean Zodiac sign is Serpens, the Snake.
- Jake calls him "Malfoy" because of his white hair.
- Michelle's Catalyst first reveals that she thinks everyone blames her for Aleister and Craig's death. Then Diego's Catalyst Idol goes onto confirm that he will be murdered by IRIS.
- He apparently speaks French as he understood Yvonne when she spoke.
- He is a skilled piano player.