A great mystery in Marvel is any of the Hell Lords the Devil or is Mephisto, Lucifer, and all of them lying.
If they are then the great unknown of is there a Satan in the Marvel universe, or is there no one supreme lord of evil.
Ghost Rider (Johnny Blaze)
For a aesthetic design or the physical look he is topnotch whether and one of the coolest most badass looking whether we're talking super heroes or characters in general.
Even though Johnny made a mistake he's still able to use it for something good.
Also even though he's a demon he's still a super hero. It's something different from the predictable cliche of demons are malevolent
Dreadful individuals.
He may be one of the greatest characters because he became a archetype and inspired others that a demon doesn't always have to be a villain. Not sure if Hellboy, ethrigan, and others would exist if it wasn't for Ghost Rider.
The i transformation along with changing of the motorcycle and his clothes.
He doesn't have the typical demon look most are familiar with including the red skin but he still looks freakin badass along with the Hellcycle.