They probably didn't want to bury the body because it's not that big an island..and he did want to stay. They raised a chunk of Magneto's old Asteroid M and declared it their own country, named Utopia, just outside the international border of California.
Necrosha is some event having to do with Selene the old mutant demon sorceress who feeds on death trying to ascend to godhood with her mutant followers help.
Why the heck an obscure character from the Godzilla comic is there, I've no idea, I don't read the regular series anymore.