Who Would Win?

Dormammu

Despot, conqueror

Dark Dimension Manipulation, Energy Projection, Matter Transmutation, Immortality, Dimensional Travel, Sorcery

None (cosmic entity)

Lords of the Splinter Realms, Lords of the Netherworlds; allied with Umar, Loki, Doctor Doom, Underchild, others

Norrin Radd

Former Herald of Galactus, cosmic wanderer

Flight, Super Strength, Super Speed, Stamina, Invulnerability, Telepathy, Telekinesis, Intellect, Teleport, Force Field, Blast Power, Healing, Super Sight, Super Hearing, Phasing / Ghost, Shape Shifter, Siphon Abilities, Size Manipulation, Immortal, Escape Artist, Tracking, Adaptive, Precognition, Energy-Enhanced Strike, Light Projection, Levitation, Dimensional Manipulation, Energy Shield, Time Travel, Empathy, Gravity control, Illusion Casting, Time Manipulation, Power Item, Energy Absorption, Energy Manipulation, Cosmic Awareness, Energy Based Constructs, Longevity, Controlled Bone Growth

Cosmic surfboard (faster-than-light travel, dimensional travel)

Annihilators, Avengers, Congregation of Finality, Defenders, Fantastic Five, Fantastic Four, Great Powers of the Universe, Guardians of the Galaxy, Heralds of Galactus, Holy Guard, Infinity Watch, Legion of the Unliving, Secret Defenders, Space Patrol, Star Masters, Super Hero Squad, The God Squad, United Front, Zenn-Lavians