Revan is another Sith who is easily Ren's superior in just about every way. He was an extremely successful combatant and general. He could defeat Ren in a fight or a fleet versus fleet battle or just about any contest.
Darth Revan is pretty much Rey's superior in every way. His Force powers are greater, his lightsaber skills are vastly superior, and he's defeated some of the most formidable warriors in the galaxy. It's doubtful he would have much trouble with her.
As further highlighted by Vader and Kylo's redemption stories, it was a lesson that Kylo Ren never fully learned himself, which makes Darth Vader the more powerful user of the Force between the two of them in Star Wars.
Many have described him as being the most powerful Force User of all time, making him superior to even Luke Skywalker and Yoda. Darth Revan had the ability to wield the powers of both the light side and dark side of the Force.
Kylo Ren is not weak, his potential is certainly as high as any of the Skywalker lineage, but I believe he simply has a misunderstanding of how the Force works, and because of this misunderstanding, he has made himself weaker.
This isn't a fight, this is a curb-stomp. Kylo would absolutely never decline a fight with Darth Vader, a force of legendary power whose surpassing will certianly gain him a place among the most powerful of the Dark Side, but he is clearly outmatched in power.
Revan's lightsaber skills must also not be ignored. Therefore, considering both experience and powers, a Jedi Revan at the height of his powers could flair well against Palpatine in a fight.
The key to Revan's power is revealed by the Handmaiden in Kotor 2, he could predict the course of wars and conflicts, presumably through the force. This enabled him to defeat enemies in battle and arrange the assassinations of those who might get in the way of his plans.
Revan's best combat feat happens in Shadow of Revan, where he fights a strike team composed of the galaxy's most powerful champions. The Outlander, who had defeated Vitiate previously, was pretty much fodderized by Revan in this expansion. Revan's best ambiental feat is summoning multiple meteors.
With a twitch, the last of Starkiller's life energy was drained away by the Force. Revan dropped Starkiller's lifeless body to the floor. Without a word, he turned and began to walk away. WINNER: Darth Revan.
Not long afterward, Malak and Revan were defeated by the Mandalorian commander Cassus Fett at the star cluster Jaga's Cluster, and Revan then ordered a large part of his forces under recently promoted General Meetra Surik to attack the Mandalorian strongholds on Onderon and Dxun.
As the grandson of Anakin Skywalker (on his mother's side), one of the most powerful Force users in the galaxy, Kylo Ren has the appropriate bloodline to destroy Palpatine. It was a redeemed Anakin Skywalker who killed Palpatine the first time, and the same midi-chlorians flow through Ren's veins.
Infil'a put up a fierce fight against Vader, almost killing him by throwing the already damaged Sith Lord off of a cliff. Despite severe damage to his suit, Vader survived the fall, and repaired himself with parts from Infil'a's droid, Arex.
Kylo Ren is a deadly swordsman and can use many Force powers, from mind-reading to telekinesis to catching blaster bolts in midair. No Mandalorian warrior, even the experienced Din Djarin, would last long if Kylo Ren made up his mind to dispose of them once and for all.
Kylo lost to Rey in TFA because he was heavily wounded and was holding back against her due to Snoke's request that he bring her back to him alive. He is also stated by Palpatine in the Secrets of the Sith book to be “equally as powerful as a real Sith despite not being one”.
The crossguard blades allow Ren's saber to operate safely – his weapon is constructed around a dangerously flawed kyber crystal, which would be overloaded if not for the lateral plasma vents that create the quillons.
Yep. Darth Maul didn't really say or show straight up that he "feared" Darth Vader, but he openly stated his belief that he could not defeat Darth Vader without the help of the Jedi, therefore on his own.
Even at an early age, Revan's insatiable hunger for knowledge and mastery over the Jedi arts drove him to be the Order's most powerful champion against the Mandalorian threat.
Primarily using Legends for evidence, Revan seems to be more powerful than Darth Bane in the Star Wars continuity. This is because much of Bane's ongoing belief in the dark side despite the failings of the Brotherhood of Darkness came from a discovered holocron created by Revan himself.
