That is an excellent idea for a collection. I actually went to the trouble of getting each of those issues individually, due to my obsession with Doom. You should absolutely tell Marvel (although I don't know that works).
Mandrakk, the Dark Monitor is bigger than, and beyond, the Multiverse. He is stronger than everyone within it, and can only be beaten by Superman, on the basis that Superman is destined to "save the day" in any story.
The awesome Parallax (Zero Hour version) can manipulate time and the universe, but Mandrakk far exceeds that. Hal is still awesome though, as hero or villain.
Doctor Strange, Doctor Doom, & Dracula vs Varnae, Baron Mordo , & Morgan Le Fey
Sorry, the title bar cut me off.
Doom - the Lord of Latveria Dr. Strange - the Sorcerer Supreme Count Dracula - the Lord of the Vampires
Baron Mordo - former student of the Ancient One and candidate for the title "Sorcerer Supreme" Varnae - the first Lord of the Vampires, older and more powerful than Dracula (also uglier) Morgan Le Fey - sorceress of Arthurian legend, one-time flame of Doom's
Doctor Doom happens upon a tiny bauble while walking through a Latverian forest one fine spring day. Being well-read as he is, he immediately suspects this to be Sauron's ring from The Lord of the Rings. Confident of his own willpower, he puts it on. Will he be able to control its power, or will it enslave him? You decide.