Excelent chapter.When Zeref said that either Natsu or E.N.D could reach him and the reason ("it would be a kill-joy") why he was avoiding Tartarus,I was sure that either Zeref created E.N.D to kill himself,or E.N.D and Mard were gonna rebel and murder him.Well,seems I was right and wrong.Oh well,I am satisfied.
I too am quite sure Natsu is E.N.D ...Zeref had an entire army of demons made to kill him,and chose Natsu to kill him,instead of E.N.D-his strongest demon?Also,when he said that of either one of them reaching him,it opens up the possibility of Natsu losing...which would conflict with what he said that only Natsu can kill him.
Zeref CURSED himself with immortality,eh?I wonder,did that guy intend to live a eternal hell?I wonder what happened in the past to make him hate not only people so much,but also himself.
Also,I don't think Zeref changed his mind.His plan to murder everyone is probably a ruse,so as to make Natsu and all guilds rally against him.Natsu wouldn't kill him otherwise.He wants to be murdered,this hasn't changed.But,I also feel that he wants to test Natsu,perhaps to see if he can slay Acnologia,so I don't think he will just give up his life without a fight.Of course,if Natsu fails,then he will progress with his plan.Maybe Zeref has some other ways of getting Acnologia killed or dealt with?Oh well,this is just speculation though.
Well,Igneel taught Natsu fire dragon slaying,and considering that Natsu can only fully master his magic by becoming third generation....he probably taught Natsu this magic so he could be killed by him.I doubt that Natsu has the balls to do it...and I doubt Acnologia will get his chance,something will get in the way.E.N.D could be the one to do it.This arc sure is promising.It's kinda a fusion of the king and Blue guardian's arcs from rave master...