4. Willpower
Doom's willpower and determination is, quite literally, second to none. Some of Doom's willpower feats include still being able to concentrate enough to activate a device in his breastplate while the cosmic entity the Beyonder painfully dissects him (see the picture above), resisting a worldwide mutation caused by the High Evolutionary - another cosmic entity - on sheer willpower alone, no-selling the telepathic/mind-control powers of the likes of Emma Frost and Purple Man using only his will, rejecting the mystical armour that the Soulsword provides the wielder with using will power alone and refusing to let a single audible indication of pain exit his mouth whilst being tortured in hell. Basically, the man's will power is monstrous.