Okay you want of evidence of Revan his power....
Lets see he did beat Malak. What does that mean, well Malak took out Kavar. Who was said to be the most powerful Jedi Master of that time, I have my doubts about that I really do. I think Vrook and Vandar were probably more powerful. But still Kavar had to be very powerful. Malak took him.
We also know that members of the high council joined Revan and Malak in their way against the Republic. They were not masters anymore, they were followers. Followers of Malak who was weaker then Revan.
We know both of them had a lot of front time experience, Malak more so then Revan but Revan still had his experience there.
The two most powerful people that couldn't use the force were both taken out by Revan in fair fights. We know the fights were fair because they wouldn't been so legendaric amongst the Mandelorians or the Echani otherwise. Mandalore was able to kill Jedi we know that much, he also took out HK-47 which doesn't mean a lot but its funny anyways. Still the point still stands. Mandalore was able to kill Jedi, he was the most powerful Mandelorian warrior and weaker Mandelorian warriors also took out Jedi.
Yussanis was a war hero with great battle pre-cog he would have logically been a great fighter, no real evidence of this however except for quotes from other people. Who do all describe him as a great fighter though. Revan took him out, when Yussanis was coming to kill him.
After that we know Revan did have the knowledge of Korriban and Malachor V, he was also a brilliant Jedi scholar according to well every Jedi you talk too, and the greatest student any of the Masters had seen. No matter which one you ask about him they all say the same thing. We know Revan had many masters but most important he had Kreia, and we all know the power Kreia had. Revan could have learned a lot from her, and he learned from her after he left the Jedi Order to join the Mandelorian wars.
We also know that Revan has the power to battle himself through the Star Forge and defeat Jedi Killing droids, that accordig to Malak could kill every Jedi in the order one on one. If Malak is right, and really we have no reason to assume otherwise that means that Revan killed many droids that each could have killed Vrook, Vandar, Kavar, Zez Kai... Now Malak could have been wrong, but the droids would still be damn powerful.
We also know he slaughtered his way through many Sith apprentices and Lords and the Star Forge security to face Malak, Sith very likely more powerful then the average PT Jedi, some of these however were masters of the high council which is impressive in even the worst of cases. Revan did go through them and then faced Malak. Malak who on his own had more power then even the most powerful of Masters at that time, and then Malak was powered by the Star Forge a dark side artifact that made him more powerful then before. More powreful then Revan could ever had imagined according to Malak. He was wrong, Revan took him out and even when Malak drained the live of a Jedi to revive himself Revan took him out again.
How many times that process was repeated we don't know, we do know however that when Malak fell he considered the fight a worthy fight and Revan greater then him. He wouldn't have done that if the fight was really worthless and Revan didn't fairly defeat him.
After that we know Revan restored his memorry something everybody that could know said was impossible. He did using knowledge that even the Jedi Council did not have. He also did this in less then six months. Which shows he had an amazing ability to learn and to learn fast. Especially if you consider all those things he had to do after beating Malak, whether light or Dark he would be burried in paper work so to speak. And still he found or created unknown knowledge in six months to restore something that was thought to be lost.
With all his knowledge back he would have been far more powerful then before.
We also know that both Revan and Malak had the force powers to destroy Rancors and Rakatan warriors at once. "They called lightning from the sky and destroyed our war beats and patrols" - Tribe of the one, Rakatan warrior.