Occlus smiles very slightly, to play up the difference in their levels of control.

"If you are quite finished with the taunts, I believe we have a duel to conduct."

"Yes. We do."

There is a designated sith duel location. It's that big open space, perfect for two sith that are trying to murder each other. Everyone watching is, of course, staying away from it, because they have some measure of self preservation.

Thanaton steps into the designated murder location.

In some places, it's traditional to bow to your opponent before dueling them, but Thanaton is mysteriously ignoring this tradition in favor of immediately trying to kill Occlus with a lightning storm.

He's usually all about tradition. She must have really angered him. Good.

Occlus will deflect his storm, then bow to him after he's finished.

Thanaton is a classy enough sith to only growl a little before bowing back.

And then? More lightning.

This storm she matches with one of her own. She doesn't block Thanaton's lightning, but allows it to flow into and through her, and then sends it coursing right back out at him.

He returns the favor with her lightning, actually.

They have now created a terrible ever-growing lightning chain. One of them's bound to lose control of it.

Occlus has something like five or six times Thanaton's maximum possible capacity. It's not going to be her.

Thanaton isn't going to let it be him, either. When he realizes that he won't win by sheer power so easily, he channels most of the lightning up towards the sky, and then the rest of the energy to send him flying at Occlus, lightsaber drawn.

Occlus dodges to the side, and turns to batter him with her own lightsaber as soon as he's within reach.

Thanaton is many things, but 'slouch with a lightsaber' is not one of them.

It's now time for the great decider among Force users; hitting each other with swords.

Hitting each other with swords is an ancient and venerable tradtion, dating back to- Occlus doesn't actually know. Or care, really. Maybe she'll look it up after she horribly murders this man and inherits his library.

Occlus's attacks are rapid and disjoint, there is no discernable pattern to them. Her movements start to leave behind ghostly trails which blur her outline and make it difficult to track her motion.

Thanaton's form is precise and perfect; every move he makes could go in a holocron for teaching his chosen lightsaber form.

He keeps up, despite the ghostly trail and indiscernable attack pattern. 

Occlus accelerates the pace of her attacks, raining blows faster and faster. Sparks crackle and crawl across her skin, and will leap out to zap Thanaton if he gets too close.

He keeps up, face a mask of single minded focus. Dark smoke coalesces at his feet and then around them, and to those watching it looks rather like the two of them are fighting in a thunderstorm.

How thoughtful of him, to provide cover like that. That will make it very easy for her to manifest a pair of ghosts behind Thanaton, which then attempt to shove him off his feet.

He realizes what's happening, and is powerful enough to resist them both -

But his lightsaber wavers an inch to the left where it shouldn't, and now Occlus has an opening with which to stab.

She takes it. That's exactly what she was waiting for.

The lightsaber goes through his torso like a - well, like a lightsaber through anything not make of cortosis, really.

Thanaton refuses to die.

Instead, he summons up a wave of power to propel himself back, away from Occlus.

"Enough of this," he growls. "I am a Dark Council member! You do not have the strength, or the authority to defeat me."

"My authority is my strength. Is that not the fundamental tenet of the Sith?"

"Your strength is siphoned from dead, better sith!"

"I exert my will, and they obey. Is that not the definition of strength?"

He snorts. "You're a parasite. Worse than your corrupt master."

"And you are a coward, running from a fight as soon as it begins to turn against you. Again. Your apprentice was a better Sith than you. He fought to the end. Not that it helped."

Thanaton growls.

"Peace is a lie, there is only passion," he murmurs, shadows swirling around him as he gathers his strength to heal himself, "through passion, I gain strength. Through strength, power. Through power - Victory!"

Occlus turns her hatred into a spear and hurls it at Thanaton as he finishes.