Doctor Strange is an undying presence in the Marvel Universe. Without him, a safe and sound Earth cannot be imagined as he deals with forces a human mind cannot comprehend. After all, Stephen Strange is the Sorcerer Supreme and there aren't many things that he cannot do.
Before becoming this magical mastermind, Stephen had to go through some intense training. He had to see how the Ancient One carried herself through the tough times, all the while trying to figure out the spells that he should and should not use, no matter what the situation demands. Doctor Strange has taken his time to master the abilities and right now, he is considered one of the most powerful Marvel superheroes of all time.
10 Summoning Weapons
Objects used as weapons play a huge role in the superhero world. While everyone has to find themselves one, Doctor Strange can simply use a spell to get himself one. Known as Object Conjuration, this is one of Strange's least used abilities because it requires a lot of concentration. He needs to put all his willpower into making an object appear out of thin air. During his early days as the Sorcerer Supreme, he could not even think of using this superpower.
9 Teleportation
Teleportation is something that many Marvel characters possess in Marvel Comics but undoubtedly, the way Stephen Strange does it is one of the most efficient. He needs to form an image of the place he wants to go and then concentrate to create a hole in time and space, using energy. The concentration part is very difficult as is forming a complete image—both require intense dedication. In the MCU as well as in the comics, Stephen struggled a lot to get to grips with this skill.
8 Astral Projection
Astral Projection cannot be achieved by anyone and there's a reason for that. A lot of superheroes who meditate can feel their spiritual form but they do not have the required skills nor the knowledge to separate the physical and astral forms.
It is done in a very subtle way but Stephen is very careful when he uses this power. He cannot let a shred of instability come in his way. It is almost an impossible skill to master for people not familiar with the mystic arts for years.
7 Unprecedented Energy
The amount of energy Doctor Strange has the means to let out is incredible. He can not only manipulate elemental energy, but he can also yield dormant cosmic energy. If he concentrates enough and uses the right spell, he can even draw power from different dimensions, like the Ancient One used to do. But the problem is that Stephen knows the drawbacks. His body could easily collapse if he doesn't do it the right way. As a result, he uses dimensional energy only when the situation is very bad.
6 Dimensional Travel
Stephen Strange had to go through a lot of practice to achieve this skill. The most important part was picking what dimension he wanted to travel to. The easiest one is, arguably, the mirror dimension, with the Dark Dimension, the Dream Realm, and Divine Realm requiring a lot of concentration and energy. The Avengers don't see a lot of this from Doctor Strange but whenever they face a supernatural entity, this ability becomes an important weapon.
5 Banishment
Banishment of any kind is a difficult skill to pull off. In the world of Doctor Strange, he can only do that if the person being banished has a lower power level than Stephen himself. Despite that, the Sorcerer Supreme needs to consider how much energy will be spent on the banishment, and will it be worth it if the attack fails? The spells are different for various kinds and places of banishment but the difficulty level is on a high level.
4 A Proper Psychic
Doctor Strange has a host of psychic abilities that he uses as and when the situation demands. He has trained himself to be resistant to psychic attacks, which means spells against him usually do not work.
Moreover, he can not only look into the future, but he can also get into other people's minds. One spell permits him to go into a person's dream. Of course, Stephen had to work very hard to develop them. He still hasn't mastered every single one of them.
3 Godly Intervention
Doctor Strange can not only manipulate large amounts of energy coming from different dimensions, but he can also call upon divine energy. This requires the use of a spell from Stephen to call upon a God named Vishanti, who seems to have developed a good relationship with the Sorcerer Supreme. Reaching a Godly being requires a huge amount of dedication and practice. And Stephen, seemingly, has the facilities for that.
2 Dark Divine Entities
A spell that can be very dangerous to Doctor Strange and planet Earth. Using this ability, the Sorcerer Supreme opens his body up for possession from the darkest of supernatural forces. He has done this with both Dormammu and with Zom. At one time, the Living Tribunal had to show up to keep Zom in check and he was convinced he will have to destroy Earth before the Sorcerer Supreme asked for a chance.
1 Ageless
To obtain agelessness, Stephen Strange had to go through something horrendous. For him to not fear death again as the Sorcerer Supreme, he had to die and do this at the hands of himself. Despite being uncertain at first, he went through the experience, and now, he is practically under a spell granting him near-immortality. He can still die of normal mortal wounds but no through disease, body failure, or age. That's the reason why he lets these dark entities into his body without any second thought.