Ryo Asuka (飛鳥 了, Asuka Ryō/Ryou) is a character from Devilman and a good friend to Akira Fudo. He is the one who is responsible for the events that happen in Devilman(the manga/80/90s/00s OVA) and has blonde hair/blue eyes despite being Japanese (since his mom was a foreigner as Akira put it in the manga). Go Nagai created him after finishing the TV series of Devilman and looking back, the show writers would have liked to have included him in the TV show.
Satan (大魔神 サタン, Daimajin Satan, lit. Great Demon God Satan, or 魔王 サタン, Maou Satan, lit. Demon King Satan) is the hermaphroditic Angel that rebelled with the Demons against God in the ancient past. S/he also created the false persona Ryo Asuka, and tricked Amon into Akira's body for his/her own desires. S/he appears in the form of a twelve winged angel, similar to the myth of Satan having assumed the form of twelve winged angel at some point in his/her life.
Ryo gives the villains his "Demonic Express Gold Card"(90009 00071) to help them out if they will help him out(which they do). Ryo reveals that he wants to go to the sun so he can face the creator of the Chibi world. During the battle between Mazinger Z/Sirene/Ghoul, the airship is damaged and needs to be repaired. On the way down, Ryo finds Sirene and she doesn't recognize him...at first. After Realizing who he is, Ryo orders her to marry the Doctor. She refuses and Ryo is about to punish her when Mazinger Z comes in! Ryo knocks Mazinger Z away with a wave of his hand(and an energy blast) and Baron Ashura tells him that the main engine is on fire and they have to land(so Ryo lets Sirene go and promises retribution). Later, they stop to gt repaired at the Getta Robo Saotome lab and pay with Ryo's gold card. Ryo talks with Psycho Jenny about Sirene and how Psycho Jenny looks the same even when Chibi. When Psycho Jenny tells Ryo about Amon's soul being sent to Kaim's body, Ryo laughs says they should be happy together. Later, while watching footage of the sun and seeing a carefree happy face (the one that created the Chibi world) he speaks with Akira (who had snuck onto the Ship) and Akira tries to convince Ryo to give up on returning to the real world and to be happy in the Chibi world. Ryo refuses to have the childlike face rule over him and does not accept the idea of finding parody in himself, so Akira leaves with the knowledge that he will have to fight his best friend. as the airship rises, Ryo sheds a tear. When they get to the sun he fires a black blast to send the corona into another dimension so he can see the real form of the creator of the chibi world. He then brings Mazinger Z and its riders into the front of the ship to show them his victory.
When Koji Kabuto gets the arm of Mazinger Z and sucked in the God head, Ryo somehow knows that it went back to the real world and that the God head is a hole in the dimensions. He tries to test the dimension hole by lowering Jinmen in it on a fishing pole but he keeps his eyes shut so he don't see anything(but they did not ask if he heard anything). He plans to send Mazinger Z in there since it has a video camera but Koji Koshiriyoku beams to avoid it. But He says his body is made of photon energy and beam weapons will not work. Akira tackles him from behind and he splits him in half with a blast wave and kills Akira. He acts like Akira is joking and tells him to stop but Akira is already dead. He gets frustrated and tells the God head to do something...And Koji tries the Koshiriyoku energy again(but at full power and on breast fire mode). After a hole is burned through the floor,he uses his power to knock over Mazinger Z and it blows up the ceiling and Mazinger Z falls into the God head... but does not get sucked in and sees scenes of Violence Jack. He takes a peak in the God head and gets startled by a close up of the face of Violence Jack. He tries to explain how the God head creates worlds and says that ideas not good enough to be manga are discarded to the chibi world. He tells the God head to revive Akira or go back in time but he says he can not so Satan(Ryo) tries to battle and ice the God head(even though it may destroy the worlds) since he does not wanna be in a world without Akira. Koji tries to self detonate to save the God head and it blows up the ship! Ryo awakens on the Violence Jack world in the nude with no memories but hates being laughed at and Violence Jack says that without memories or weapons, he can restart.
After Satan killed Devilman, s/he regretted this action. So s/he made the Slum King to punish him/her to make up for what s/he had done. In Violence Jack, Ryo is in love with Miki Makimura and they are somehow alive and human at the start of Violence Jack. They had jobs in the Restaurant King (the Slum King's restaurant) until they ran away and got caught having sex, by the Slum Kings men. They were paraded around in the nude around town and later had their arms/legs sliced off and pegs put on their stumps so they could walk. The Slum King mistreated/abused them and when Ryo's until then unseen sister Honey Asuka, comes to save him, she is horrified by his limbless/nude appearance and later bombs the Slum King's base. At the End of the manga, when Honey and her friends get killed, Ryo and Miki help Jack defeat the Slum King and die trying. Later, Ryo returns to being Satan and kills the Slum King for good before resuming his/her fight with Devilman.
- Markmanship: He is able to fire a shotgun/hunting rifle, and a sniper rifle with ease and accuracy.
- Demonic Detection: As seen in the Verotik Devilman Comic, Ryo can sense when a Demon is nearby by it's scent. Also, Ryo suffers from dizziness and a headache moments before a time slip appears. While Devilman was trapped in Sirene's claws Ryo's subconscious awakened him to save Akira.
- Superhuman Strength: After acquiring the powers of Satan he can fight on equal terms with Devilman and Amon in hand-to-hand combat. He is also very resistant to physical pain as he was shown retaining his composure even after being assaulted by a large crowd he provoked at a club.
- Healing: Repair his body from injuries that would have killed him otherwise. When he was seriously injured during Akira's rampage through a night club, Ryo was later able to heal quickly once Akira returned to check up on him. Also, when he had his limbs severed by Slum King, Ryo was later able to regrow them and fight against the Slum King on equal terms. He can also use his healing ability to heal the wounds of others, such as being able to heal Devilman's severed arm after his fight with Sirene.
- Martial arts: During the incident at the club, Ryo was shown to be easily capable of dispatching opponents with ease in close-quarter combat, such as using a broken beer bottle to injure several club members and being able to take on the large crowd before being attacked himself.
Ryo is an extremely calm individual possessing incredible charisma, being able to manipulate or convince others to do his bidding. He is also shown as being highly intelligent. However, He is more foul-mouthed and ruthless in the English dubbed versions of the OVAs, frequently cursing in almost every speaking line (In the English dub, he also appears to have little to no concern for traditional Japanese customs). He even goes so far as to say how it would be better for humans to be killed by demons. Despite his cold personality and having the powers of Satan, Ryo is not without humanity as he protected Akira and Miki from a gang of bullies by brandishing a firearm at them and even showed remorse after killing Devilman.
- Iron Virgin Jun: In here he first shows up in a closet and dressed like a magician with a Bat. He brings Jun Asuka to a party where he touches her left C cup (Wait, I thought he loved Akira and said he didn't like chicks?) but then apologizes. Later he has Akira Fudo KO Jun and bring her to him unconscious. He chains her up and plans let his grandfather take his revenge on her by raping her. The old man comes in with a goat mask non but starts crying, thinking it was his wife (Jun's grandmother) come back to him, and Jun breaks out of the chains and Ryo lets her on her way the next day.
- Devil Lady: In here Lan Asuka is basicly a female Ryo but turns out to be half of Satan and later has a kid with the other (Jun Fudo) half after becoming male or something and later fuses with Jun to make Satan.(In the Anime she's just a Female who has alot in common with Ryo in looks and other).
- Yu-Gi-Oh! : Kazuki Takahashi's character Ryō Bakura was influenced by Ryō Asuka. In fact the Kanji used for Ryō （了） are the same. Parallels between the two characters go on and on throughout both series. Mostly due to the characters being close friends of the protagonists and eventually becoming the final antagonists at the end of their respective series.
At one point, Ryo mentions the portrayal of Lucifer in Dante Alighieri's Divine Comedy where Lucifer/Satan was sealed away in ice as punishment for the sin of treachery. Whether or not Ryo's form as Satan is this exact same Lucifer however is unknown.
In Abrahamic myth, Satan was originally a regular, but powerful angel who tested the faith of humans through torment with his most notorious target being tormenting Job by making him lose everything he worked for in the hopes Job would curse God and lose his faith, but Satan was forbidden from actually harming Job. Later on, Satan became considered one and the same with the rebel angel Lucifer, who was said to have assumed the form of a twelve winged angel as one of his/her forms.
The name Asuka is derived from the Akshobhya, one of the Five Wisdom Buddhas.