User blog comment:CNBA3/Dragon King Festival and E.N.D/@comment-24039250-20140501185034

When comparing Rave to Fairy Tail here is how I see it:

Zeref=Lucia

Acnologia=Endless

END=Megido (He was the king of the 4 demon lords)

The difference I see with Fairy Tail and Rave is that Acnologia (Endless) will fall before Zeref(Lucia), since killing Acnologia would be prove to Zeref that Natsu is ready to fight him(obviously Natsu will be the one since HE'S Natsu). I can even see this happening in one chapter where after Acnologia is beaten, a panel of Zeref shows up with him sensing this and him saying that Natsu is finally ready and "The Final Battle is about to begin."

As for End, while he is a threat, when compared to Acnologia and Zeref he is nothing. However since End is Zeref's most powerful, he would still be seen as Zeref's second in command so to say, which is why I categorized him as Megido, the King/Ruler of the 4 Demon Lords (since Megido worked under Lucia as his second in command).