Black Manta is Aquaman's oldest and most hated villain. A former treasure hunter under his dad, Black Manta developed a lifelong grudge against Arthur Curry after he killed Manta's dad. While he has had a few side projects in the past, Manta has shown time and again that he wants nothing more in the world than to see Aquaman die.
Ocean Master, aka Orm Marius, is the half-brother of Aquaman who has an obsession with obtaining the throne of Atlantis. While Aquaman has often shown that he has no interest in the role of king, he has had to take the throne to keep Atlantis from being ruled by the despotic Ocean Master. As such, Orm has grown to hate his brother...almost as much as he hates surface-dwellers. Both are worthy foes to Aquaman but who is his greatest enemy? Who deserves Aquaman's hatred the most? Here are 5 reasons why it's Black Manta and 5 more why it's Ocean Master.
10 BLACK MANTA: His Only Goal Is To Kill Aquaman
As previously indicated, Black Manta's only goal in life is to kill Aquaman. While Ocean Master has grander goals and schemes than simply killing his half-brother, Black Manta believes he will finally know inner peace once Aquaman is dead.
During Brightest Day, Black Manta was shown working peacefully at a seafood restaurant when he discovers that Aquaman has come back from the dead. This sends Manta into a rage, where he kills everyone else in the restaurant and renews his mission of murder. So long as both Arthur and Manta draw breath, Black Manta will work tirelessly to kill Aquaman.
9 OCEAN MASTER: His Superior Atlantean Physiology
Like Aquaman, Ocean Master is a full-blooded Atlantean. That means that he has the enhanced strength, speed, and durability that comes with being an Atlantean.
He is Arthur's physical equal in every sense of the word, which is something Black Manta cannot claim. Orm can also fight underwater without a breathing apparatus, which is the main purpose of Black Manta's iconic costume. But even without weapons and gadgets, Ocean Master is a threat to Aquaman.
8 BLACK MANTA: He Killed Arthur's Father
When he was a young man, Black Manta was hired to steal a sample of Arthur's blood and was discovered by Arthur's father. In the struggle that followed, Thomas Curry had a heart attack and died.
This is what led to Arthur mistakenly killing Manta's father when he intended to kill Manta himself. This was the genesis of the lifelong feud and the first time Manta took something away from Aquaman.
7 OCEAN MASTER: His Legitimate Claim To The Atlantean Throne
Though he may be a ruthless tyrant, Orm Marius is still the son of Atlanna, giving him legitimate claim to the throne of Atlantis. In fact, he has ruled the underwater kingdom in the past.
This means that Orm will always be a threat to the sovereignty of anyone who rules Atlantis. It also means that he could likely rally an army of fanatical Atlanteans to his cause in the right circumstances.
6 BLACK MANTA: He's A Killer Through & Through
Black Manta is also a highly skilled combatant who has gained an arsenal of weaponry. While Orm has the strength, Manta has the skill.
Black Manta has honed himself to be a living weapon bent on the death of Aquaman. He was even recruited into Lex Luthor's Legion of Doom, though Manta betrayed the team when it no longer benefited his goal of ending Arthur.
5 OCEAN MASTER: His Magic Trident
Like Aquaman, Ocean Master has a magical trident of his own. It was constructed hundreds of years ago before the sinking of Atlantis. Like the Trident of Neptune, Orm's trident can call down a storm and emit electrical blasts.
It means that Orm has a weapon on par with the powerful Trident of Neptune, and it could give Orm the edge in a fight with his brother.
4 BLACK MANTA: The Mecha-Manta
Recently, Black Manta gained a new and unforgettably powerful (read: awesome) weapon: the Mecha-Manta. It's a giant robotic mech with an AI based upon Black Manta's father that was gifted to Manta by Lex Luthor as a weapon to use against Aquaman.
Ironically, Manta forcibly changed the AI's personality to be more malleable and easier to control. Manta changed the true identity of his father to better shape his idealized memory of his father, and it ironically made the Mecha-Manta a more lethal weapon.
3 OCEAN MASTER: He's An Expert Strategist
Ocean Master has proven himself an expert strategist on several occasions. He knows how to command an army, and he even hired Black Manta to kill Aquaman during the villain's first appearance in the New 52 DC Universe.
Ocean Master knows how to damage his enemies from afar, and he knows the right pressure points to hit on his path to victory.
2 BLACK MANTA: He Killed Aquaman's Child
This one dates back to older DC lore, but it's arguably what made Black Manta one of the most memorable DC villains of all time. Way before Crisis on Infinite Earths, Aquaman had a child with Mera. However, during one of Black Manta's mad rampages, he suffocated Arthur's child.
This is the worst thing Black Manta has ever done to Arthur and Mera, and it shows how deep his hatred of Aquaman goes.
1 OCEAN MASTER: He's A Sorcerer
This one also goes back before Flashpoint so while it may not be canon anymore, it's still worth mentioning. Ocean Master used to be a sorcerer, able to conjure magic even without his trident. He even had his magical abilities advanced by the demon known as Neron in the Underworld Unleashed story.
Sorcery may be a skill that Ocean Master can recall in upcoming issues of Aquaman, and it could be the way he finally gains victory over Arthur.