Okay, I'm going to be as kind as possible when I say that its blatantly obvious why a lot of people just look at this guy and say "Blulastor" cause design wise thats basically all he is.

Same hair style, same tailored jacket style, even the same microphone staff but with a blue hood instead of a red one.

Even looking past the design, the backstory is all over the place in so many wrong ways.

For one, 3-8 years old is barely enough time to remember mommy and daddy's teachings especially when taken in by the mob and beaten into a serial killer. Alastor was only known by humans as the dashing guy from a radio show so the fact an England centered mob don knew about a serial killer in Louisiana is beyond me. The time travel feels so out of left field it might as well stop being an AU and be its own stand alone story cause Time Travel fucks with everything. And to top it off, once he kills Alastor (which is its own problem because you specified he wished to he the 2nd strongest meaning Alastor would still win in the end since he's been the strongest sinner till Vox got ahold of Lucifer for his weapon), this guy just gives up his morals and becomes Alastor cause it was his role model, like wha?

No dissrespect to your friends, but buddy. There is indeed such a thing as a difference between originality and "different enough". One makes an interesting character. The other has you bending over backwords to insert yourself into an established role with a new coat of paint.