Gah... This is sort of devastating... I was really looking forward to this one!!!

what a shame. I wonder if its editing the devil aspects or just marketing ?

The demonic transformation is a Japanese cultural aspect that doesn't quite make as much sense in Western culture, which is why it's apparently being downplayed (not acknowledged in the title), but it's still both relevant and innocent enough not to be worth editing.

I think a lot of people have unrealistic preconceptions over NOA's censorship standards if they truly think NOA will go out of its way to edit-out all devil references for religious-sensitivity. If you look at other things NOA has released here, it's pretty clear they aren't NEAR as sensitive to that kind of thing as people seem to think (demonic and devil figures appeared in plenty of their own games).

The myth largely seems to stem from the fact that, Devil World was never released here, combined with the odd fact that Tamagon's trophy in SSBM had its game title altered to "Demon World" in early builds of the NA version of the game, then ultimately removed from the final release (even though it was also removed from the PAL versions where Devil World actually WAS released). Whatever the reasoning behind that odd move actually was, it's near certain that it wasn't simply the devil reference as many assume, but we'll likely never know for sure.

The reason Devil World itself wasn't released in NA was because it featured the Bible and cross-shaped stage designs, not just the actual Devil itself.

I assure you, the devil-aspect isn't much of an issue for this game, so it's by far a much safer guess to assume it's for marketing reasons.