He shall rise again it is said. But what can he do but fill his armies whit malice. His body is broken and his armies dead. His malevolent beasts are slain or routed from the world. Where then would he get a army powerfull enough to battle the Valar. In my mind only mortal men who desire power would hear his call. For he cannot make anything that has a life of its own and thus he cannot raise his armies to the demise of the undying lands. And as he is himself imprisoned and the mightiest of his servants is exiled how then can the final battle begin but for the wish of Eru. Surely the men of westernesse shall not stand whit him for in them flows a blood nobler than in others. The evil peoples of Khand and Harad might of cource join him but their power alone could not destroy the fortified home of the valar that hath been lifted from the circle of the world.
Elves who truly hated the black one would never believed his lies again even had he been in the fairest form ever seen in arda.
Here then are my questions:
1.) Why would Eru who loved his children wish them to go trought pain and suffering by reviving the armies lost to morgoth
2.) From where would he get his apocalyptic army?
3.) His body is broken and much of his power is lost where would he get the strenght to break the chains that bind him?
edit: just as a afterthought i would like to thank vir for reminding me that morgoth would return... and i know there can be no specific answers (though i am known to be wrong at times) i would ask you for a theory or thoughts or anything
