You do know Martian Manhunter isn't actually weak to fire, they're only afraid of it. Now with that being said, Dr Fate still wins even unless his spells cannot affect Martian Manhunter when he makes himself intangible.
The Manhunter from Mars has a great fear of fire, often becoming powerless when confronted with flames. Since Doctor Fate can create fire, he has the power to take down Martian Manhunter with ease.
Nabu: Nabu is an ancient and powerful magician who has been a recurring enemy of Dr. Fate. In some storylines, Nabu has been able to defeat Dr. Fate through his superior knowledge and control of magic.
While jointed, Doctor Fate is considered to be among the most powerful magical beings on Earth and even potentially more powerful than Kent Nelson's incarnation although they lack his experience.
However, in terms of who would win in a fight, I'd still give the edge to Doctor Fate. Both Doctors have similar abilities, but I think Marvel just shows them better. Here are some examples.
Thanos is powerful enough to challenge entire teams of heroes, his cosmic might allowing him to run through even the most powerful heroes with little fuss. However, Doctor Fate has the power to defeat Thanos rather handily.
MCU Thor has moved the rings of Nidavellir and held open the Dyson Sphere which is Moon level in Strength. He also has resisted the Bifrost. Star level easily in strength. Hence, Thor is stronger than Doctor Fate.
Using his Nth Metal mace, Hawkman amps his striking power. Superhuman speed: With his suit, Hawkman can run and jump far faster than peak humans, this speed is mainly manifested in his flights, which allow him to travel between locations in a matter of moments, as well as chase down his enemies.
A being of immense magical power, Doctor Fate is one of the front-line heroes relied upon to deal with major threats to the planet, and an appearance by Galactus would certainly qualify as one. Despite his formidable abilities, it's entirely possible that Doctor Fate would be overwhelmed by the World Devourer.
It's also worth mentioning that the ghost Rider is next to unstoppable. The only ways to truly kill him is with an act from God or holy weapons, both of which are things. I am pretty sure Dr Fate doesn't have access to. I'd say ghost rider, but you could make a pretty good argument for either victory.
Spawn is the only character in Image Comics that Martian Manhunter couldn't defeat. Martian Manhunter is not only close to Superman in physical power, but his other powers like Martian Vision, telepathy, telekinesis, shapeshifting and phasing would make him very hard to beat.
Hyperion's power levels are on par with those of Superman and while J'onn has some extra powers that even things up, Hyperion's heat vision would be all he needed to take down Martian Manhunter.
Who would win in a battle between Doctor Fate and Shazam? Dr. Fate was capable of restraining black Adam and even standing up to sabbac before he eventually overpowered him. ShaZam is a child with the powers of a god, he won't know what to do so that's why he looses this one.
Loki is no slouch in the magic department, but Dr. Fate would be able to take him out. The Helmet of Nabu grants Dr. Fate with all the power of the Lord Of Order the helmet is named after and all of the knowledge of spellcraft that immortal being possesses.
Wotan is frequently portrayed as the primary antagonist of Doctor Fate. Originally a female who obtained her powers through sorcery, Wotan later underwent reincarnation in a male form.
Fate's main weakness is that his physical form can be stressed and destroyed. It is also revealed that Dr. Fate was not meant to be either male or female, but both united as one, and that unless this is realized Dr. Fate can never reach his full potential.
Sentry is definitely more physically powerful than Dr. Fate. However, Fate doesn't have to just rely on his physicality. He can shield himself from The Sentry's attacks and use his magical might to take him down.
Highfather from DC Comics is far more powerful than Odin from Marvel. Although he has much less feats because he's too powerful, he still has some feats. And it's those feats that I'll be using to establish why he's more powerful than Marvel Odin.
Odin and Zeus are considered "roughly" equals among the Council of Godheads in Marvel. I say roughly because Odin vastly surpasses Zeus in feats shown in comics, but it has been stated before that they are equals.
