In the course of Revan's life, two lies stand out above all.
The first was several years ago, back when she and Malak were in the process of becoming Sith. During their search for the Star Forge, they located Star Maps on five worlds: Dantooine, Kashyyyk, Manaan, Tatooine… and Korriban.
Korriban was easily the most fun. A Sith world, it filled their heads with such potential, such fire. Making their way through the long-sealed tomb of Naga Sadow, they eventually came into a large, round room, circled by statues and covered by the dust of centuries. The great Star Map, dormant for so long, blossomed slowly open, revealing, in glowing blue, the final information the two fallen Jedi needed.
Knowing, at last, where they had to go, they walked back outside, into the Valley of the Dark Lords, bathed in the light of the setting sun.
"Revan?" Malak began, staring at the valley in all its glory, "does this make us Sith now? I mean, we've defied the Council, found all the maps… and we're so close to finding the Forge itself."
"Nothing 'makes' us Sith," Revan replied. "Nothing but our own choices. We are Sith because, that day on Dantooine, we both chose to walk into the temple. And we chose to live with, and embrace, the consequences." She didn’t even need to add 'and each other.'
Malak still seemed a little hesitant, and now Revan could definitely sense something from him… something as strong as worry. She looked at him in a tell-me-the-problem way, not needing to say anything in order to persuade him to respond.
"So… does that mean that I'll have to kill you one day?" Malak said, finally.
"That… or die trying," Revan replied. She'd never admit it now, but there was a lot of reluctance behind that statement.
"But… it shouldn't be that way," Malak insisted. "We're different, you and I. We know what we both went through… what we're still going through. We're more than just…"
"…master and apprentice?" Revan concluded. "Yes. I suppose we are." That was a good thing to say… Malak really didn't like the idea of being the 'apprentice.' He never had.
She half-smiled, putting her hand on the side of his face. "Malak… you are right. Things can be different. If we stand together, we can fight together. We can be at one with this wonderful new power. If you choose not to betray me, I will never give you reason to. And there will be no final duel."
And her whole being cried out liar! She should have listened. She should have vowed, there and then, to keep the promise she'd made.
She didn't. She kissed him instead, lost in the passion they were both overwhelmed by.
Three years later, he betrayed her. Five years later, she killed him. They should both have seen her lack of sincerity for what it was.
And the second lie… ah, the second is much simpler.
"Carth… I am not her. Not anymore."
And the consequence of that? He believed her too.
He shouldn't have.
Summary: She's told so many lies... but it is just two that have really made all the difference.