Top 10 Most Powerful Supernatural Characters

God

As they were born around the same time and are both primordial beings, God and Death both possess an immense amount of power. Just like Amara, they are also referred to as omnipotents.

He was one of the most powerful beings.

The Darkness

Sorry to disappoint you, but if God truly had infinite and unlimited power, he could have resurrected both Raphael and Gabriel from The Empty without much difficulty. Even if the cosmic entity wouldn't have wanted to let go of some archangels, for example.
The Darkness herself may be near-infinitely powerful, but not powerful enough to revive archangels from The Empty. And perhaps because no one literally has infinite, unlimited power, no one can bend rules or anything with ease. That's what I think.

Being the oldest being in existence and the first primordial being, as well as God's older sister, Amara possesses near-infinite power and nearly killed God himself. She is referred to as an omnipotent, someone with near-infinite power.

Jack Kline (Nephilim)

I would think that The Shadow could help Jack Kline become powerful, like a literally infinite and unlimited amount of supernatural power. He could even help Jack become highly nigh-omniscient or even omniscient if The Shadow knew that one day someone could be born or created, becoming equal to him in raw power.
It would be fun if The Shadow helped Jack, and if they both held infinite power at some point - for example, during the final episode of Supernatural, if The Shadow directly stepped in during the final episode or in the last couple of episodes of season 15. It would be a fun thing if Jack and The Shadow could make a new natural order and create a new balance, even if it meant that God died and perhaps The Darkness as well.

Michael

The most powerful and fierce angel. Michael is one of the most feared beings in the supernatural universe.

The Cosmic Entity

I do think THE COSMIC ENTITY resurrected, rebuilt, or restored JACK KLINE's physical body and sent him back into creation and the original universe. Some believe that Billie was responsible, but if that's true, why do they rank her lower in terms of nigh-omnipotence? If THE SHADOW a.k.a THE EMPTY was endlessly more powerful, some try to downplay its power because of a few restrictions or limitations. However, if THE EMPTY had infinite power, it still couldn't force someone back to sleep or stop GOD from resurrecting a few beings from THE EMPTY.

I wonder if THE COSMIC ENTITY had infinite and unlimited power but not infinite knowledge, or if there could be another cosmic being with both infinite power and knowledge. Imagine if, at the very beginning, there were two twins - a male and a female - who were both omnipotent and lived in The Empty for eternity. If the female cosmic being gave birth to THE DARKNESS and GOD, would that surprise you?
I also wonder if THE COSMIC ENTITY tried to corrupt THE DARKNESS first, then LUCIFER, and eventually other entities like the Leviathans. Would JACK eventually grow to become omnipotent and possibly nigh-omniscient, or even omniscient? What would it be like if JACK had infinite power and battled THE COSMIC ENTITY, weakening him? Then, GOD, THE DARKNESS, and even DEATH, THE PRIMORDIAL HORSEMAN, could join in to further exhaust THE COSMIC ENTITY.
If JACK became powerful enough, he could revive thousands of angels, restore ARCHANGELS from The Empty, and even revive DEATH, restoring his physical form and powers. He could release Michael from his cage, cure his madness, and free LUCIFER from corruption. Imagine an incredible event like this, where JACK teams up with all the ARCHANGELS to fight THE COSMIC ENTITY.

Gabriel

The youngest among the four archangels, just like the rest of his brothers, Gabriel also has an extraordinary amount of power and was among the first of God's creations.

Lucifer

As the second-oldest archangel alongside Michael, Lucifer is the king of all demons and can kill multiple pagan gods at a time. He is also one of the oldest beings in the universe and is one of the most feared beings in the Supernatural universe.

Castiel

Castiel is a fictional character portrayed by Misha Collins in the CW Television Network's American television series Supernatural. Introduced in the fourth season, Castiel is an angel who becomes a close ally of protagonists Sam and Dean Winchester. His character is known for his deep voice, trench... read more

Not thousands, it was millions of souls.

Was able to overpower Raphael with a snap of his fingers due to the thousands of souls from Purgatory.

Death

I mean, come on, Death can literally predict every possible future. So, if Dean was going to kill him, he already knew. That's why that "not impressed" face when he "died."
He said he will replace God some day, and that's true. From the moment that a living being, whichever it is, appears, its expiration date appears with it, and that expiration date is called Death. So, whoever came first (God, Darkness, or Entity), they didn't come alone.
Even God, Darkness, and Entity must die some day, and only after all beings are dead will Death die. Death is the beginning and the end of life.

It should be no. 2. As he was capable of killing God-juiced Castiel. That's why the Winchesters were using him. He just didn't want to mess up the balance of nature. That's why he didn't kill him.

Billie (Death)

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Loki

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Metatron

Raphael

As the third-most powerful archangel, alongside Lucifer, Raphael also has an extreme amount of power. Being an archangel, he and his brothers were among God's very first creations.

Cain

Dean Winchester

Dean Winchester is a fictional character and one of the two protagonists of the American drama television series Supernatural. He is portrayed by Jensen Ackles and is known for his tough demeanor, love of classic rock, and strong loyalty to his brother, Sam. Throughout the series, Dean hunts supernatural... read more

Number 4 because he killed everything bad and can kill anything.

Jesse Turner (Antichrist)

His feats are beyond any other character in the show.

Eve

As a primordial monster and even predating angels themselves, Eve was a very powerful monster who could change humans into the type of monsters she wanted with a touch. She was also extremely difficult to kill.

Alpha Vampire

Leviathan

Dick Roman

Demon Dean

From what we know, Dean killed hundreds. We don't know a lot about his time as a demon, except for minor flashbacks. But we do know that he was more powerful than any angel or demon walking around Hell. Even Crowley, the King of Hell, feared him.