Although Astral has amnesia, he has a very intelligent and calm attitude when it comes to Dueling. Even in disastrous situations, he does not seem to lose his cool and can think of a strategy to get out of it. Outside this, arguably because of his memory loss and sudden arrival to another world, he is curious to the point of naivety, for matters as simple as eating, going to the bathroom,[20] or believing that TV shows are real.[21] His naivety would go to such extent so as to ask Yuma why "he needs to be alone" when Yuma's in the bathroom, to which he replies by saying that anyone who sees him in there would "die" (in the dub, Yuma says that that someone would turn into a "guinea pig") otherwise, a thing that Astral took literally.[20]

When he "discovers" things, he has an habit of saying "observation number one, two, three" (which used to annoy Yuma) and then speak the result of his analysis; the fact that he can successfully continue the counting throughout the series implies he has great memory. Astral's observations stopped after their first Duel with Kite Tenjo, which left him quiet and depressed.[22] However, after their Duel with Fortuno, which restored his and Yuma's confidence, his observations returned. In the dub, this observation came with a "sub-observation" that he labelled #13-A.[23] As Astral continues to learn about the human world, he showed great interest of feelings and friendship from observing Yuma and becoming more human in the process. During a Duel with Vetrix, Yuma started to eat the rice balls that Tori gave him prior to the Duel which allowed Astral, who was fused with him to feel the sensation of eating for the first time. He felt incredibly energetic and lively by the taste of the rice balls, stating he wanted to eat "two, or three" more of them, while cheerfully saying that being Yuma has been fun in a rather comedic instance.[24]

Astral has a fear of cats, which he defended by claiming that he hadn't done any observations about them,[5] but seems to gotten over it later on.[25] After Dueling with Kite Tenjo for the first time, he developed a strong fear towards him, so he always tries to tell Yuma to run from Kite instead of fighting him, to the point of telling Yuma to forget his friends. He first denied that he was afraid of Kite, but later admitted.[26] Later during the Duel with Fortuno, Astral overcame his fear and decided to actually fight. After he and Yuma thought about their previous Duels, stating they came too far to lose now, Yuma called Astral his friend, restoring his fighting spirit.[23]

During their duels, Astral often says "The winning formula is complete" whenever he and Yuma are ready to make their comeback.

Usually stoic and cool, Astral does not smile much, but he smiled for the first time when Yuma recognized him as his comrade.[23] Afterwards, Astral begins to smile more often at Yuma since then and even cheered him on with his friends and family when he was trying to do his 20-stack challenge.[27] He still retain his withdrawn nature and tendency to keep his most of thoughts to himself. When observing and learning things unknown and important to him, Astral will only voice speculations once he gathers more evident proof or when a problem presents itself, such as telling Yuma about the world inside the Emperor's Key only after gaining a handful of "Numbers" cards and learning of its origins.[8]

Later, Yuma pointed out that Astral was starting to act like him, more daring and willing to take risks, much to Astral's denial.[28]