"We're waiting on two things, whichever comes first will let me kill Melkor. One of them is one of the set of rocks the maniac has. My universe has a similar set of magic rocks - sometimes things are similar world to world on a smaller scale than 'the entire place is an Arda' - and I can use my instance of one of them to kill Melkors within one step of my home world, no problem. Ability to use infinity stones, that being this kind of magic rock, depends on the rocks liking you - an infinity stone is an inanimate object in sort of the same way Huan is a dog, if that makes sense - and this one doesn't know me yet but I convinced it to talk to me and it told me to do something interesting. If it decides I'm interesting enough, and I'm hoping 'go to an Arda' is interesting because the first time I went to an Arda it was because mine sent me there, I should be able to use it like the one at home and I currently expect it to have a similar scope of power.
"Second thing is my various alternate universe versions and various Ardasfull of Elves and so on, who collectively form a multiversal organization. I have an alt who can portably destroy Melkors; he'll have to come here, so it waits till they've found a path from the known map to this world, but after that he can bang it out in a few hours."