I see
Axel as a normal legit name (I'm Dutch) and I prefer
Axel over any other spelling. Axle looks 'made up' to me. Axl looks a little weird as well.
Axel is a nice name I think and deserves a bit more attention than it's getting.
Siblings to
Axel:
brothers:
Karl,
Erik,
Kurt,
Bastian,
Mathis,
Stellan,
Sander,
Jasper,
Caspersisters:
Elsa,
Heidi,
Johanna,
Lovisa,
Freya,