The Witcher 3 is enormous in scale, so, of course, that means it's jammed full of nasty monsters Geralt of Rivia has to kill. But, are all monsters genuinely evil? Yes, some will have an ulterior motive, but others might have a reason as to why they became who they are.
However, what monsters are genuinely mighty and what ones are pretty weak? Powerful doesn't only mean strong; it could be devious, and it could be setting the Witcher on a path that will harbor many regrets. Perhaps the power comes in making Geralt scared, or to even provoke him into breaking Witcher code.
10 Powerful: General Of Ice
Imlerith is a general and a very formidable warrior of the Wild Hunt. Geralt want's revenge against this foe, and also wants to stop the Wild Hunt from hunting Ciri. Imlerith's power comes from his monster strength, but he also made Geralt's Witcher code to become null and void for the instance of this battle, as how could Geralt remain neutral?
Geralt can use his mutant speed against the slow bulk of Imlerith, but the difference in strength is astonishing. Halfway through the fight, Imlerith decides to forgo defense and go straight for pure offense, he throws away his gigantic shield and puts two hands upon his mace, as he twirls around the battlefield like it weighs nothing. Upon his defeat, Geralt uses the Igni sign and focuses his fiery rage upon the enemy that killed his father.
9 Weakest: Fire Elemental
This elemental was summoned by Phillipa Eilhart for no other purpose than to kill. It has no mind of its own, so it's weak in that regard. It's only strength is its use of fire that it wields naturally, and that it doesn't feel fear when it dies. This boss isn't significant; it's there to hold Geralt up while Phillipa can escape.
This boss is quite an easy boss to defeat, as Northern Wind and Aard can make short work of this creature in combination with striking it once it's flames have disappeared. Of course, no matter what happens, don't start playing with Igni, as that can only end badly with a very well-charred Witcher.
8 Powerful: High Vampires Are A Pain
When it comes to monsters of The Witcher 3, sometimes it's best not to look at their backstory, as some are not as evil as they seem. One that fits this bill is the higher vampire Dettlaff van der Eretein.
A monster known as the Beast of Lydia killed 200 people, and Dettlaff did not care. However, when he learned the beast murdered a young boy who offered the vampire an apple the day before for nothing in return, he immediately went and slew the monster. Dettlaff views the world in only black and white, entirely based on his perception of right and wrong. The beast was black, and the little boy was white, a mindless simplicity that can be extremely deadly. This is why Dettlaff is so powerful.
However, Dettlaff's values were thrown out the window because of love when his beloved Rhene was abducted, and her abductees ordered him to kill five people.
7 Weakest: Madman Lugos
Humans can be pitiful creatures; some might be strong and powerful, and others might be weak, but their hearts filled with malice. Madman Lugos wasn't anything significant, the only thing he had in spades was his furious violent temper. This rage is why he is so well known, and his anger is why people step aside when they saw him coming.
In reality, he is a pathetic man with no redeemable qualities at all. He gets enraged when his son isn't chosen to be the next ruler of Skellige, and in this madness, he attacks Geralt of Rivia which was an abysmal last decision.
6 Powerful: The Hags Of The Swamp
These foul beings that live here are known as the Ladies of the Wood. They control the swamps around Velen and some of the closer unfortunate settlements. And what tribute do these Crone's want? Ears, of course, because they use ears to monitor the woods.
These are powerful because of where they live; they own the swamp, as it's their place of power. Geralt has no idea what these three are truly capable of, and, even with back-up, he's afraid. With their ears listening to everything around, they know who's coming, and a mage who's got time to prepare is incredibly hard to kill—and remember to multiply all of this by three.
5 Weakest: The Tree's Heart
This quest goes hand in hand with the Hags of the Swamp, as the Crones asks Geralt to go and kill a powerful enemy, which resides in a giant tree. Upon investigating more, the spirit in the tree offers Geralt a deal: have Geralt free her, and, in return, she will save the orphaned children from being eaten.
However, the spirit has been killing any human who comes near, entirely for self-preservation. This seems unnecessary, as no human is going to wander anywhere near with monsters such as werewolf's patrolling outside. The tree is weak, killing innocent's just for the slight chance they might stumble on the heart of the tree.
4 Powerful: The Man Of Glass
The price of the wishes from the Master of Mirrors, or his real name Gaunter O'Dimm, is your soul. And souls are his favorite thing to bet with.
Geralt, having killed the Ofieri Prince, was being sentenced to death. By chance, of course, O'Dimm appeared and offers to save Geralt for free, but in return of a small favor. Geralt agrees, and, as soon as the deal is struck, he was marked by O'Dimm as a sign of their bargain. O'Dimm is powerful due to his deviousness and in his use of wordplay to find loopholes to trap you. From what seems clearcut to you, no doubt the Man of Glass, has already ensnared you completely. What might be a simple favor to you might be lifetime debt to O'Dimm
3 Weakest: Salma The Succubus
Succubi are well known for their seduction and deceit, but those who end up in her bed will have a night of ecstasy but might end up dead. Geralt accepts a contract from a group of Temple Guards to hunt down and kill the fiend that is behind a string of murders. All evidence leads to a succubus, such as how the victims died by exhaustion.
Upon finding Salma, she denies all involvement and states that the killing of guards was in self-defense. As a contract, as a monster, Salma is weak but a weakness that harbors no ill will towards Geralt. Does she deserve to die?
2 Powerful: The Air Djinn
There are four types of genie, which are based on four elements, air, fire, water, and earth. If you happen to find one and bind it to you, they shall grant you three wishes. These beings are powerful enough to grant real wishes, but be careful with your words, because words are crafty.
However, the fight between Geralt, Yennefer, and the Djinn also holds a very emotional weight to it. As both Geralt and Yennefer want to know if the feelings they have for each other are genuine or if it's all from a wish Geralt made years ago.
1 Weakest: Eredin The King Of The Wild Hunt
All throughout the Witcher 3, the Wild Hunt has been breathing down your neck—and Ciri's, too. You come to believe that Eredin the King of the Wild Hunt must be some extremely powerful, and, to control his strong underlings, he must have an iron fist, especially when he killed the previous king to become king himself. If that is the way of the Wild Hunt, then the reason why Eredin is still on top is that he's the strongest, surely.
But, in actuality, Eredin was a weakling who hid behind his soldiers and talked big when he had his support of guards to fall back on. His fight to end the Wild Hunt was disappointing, but also so, so satisfying.