Condition:

Age was beginning to take its toll on Bane, but it was nothing compared with the toll already wrought upon his body by decades of drawing upon the dark side of the Force. He couldn't help but smile at the grim irony: through the dark side he had access to near-infinite power, but it was power that came with - a terrible cost. Flesh and bone lacked the strength to withstand the unfathomable energy unleashed by the Force. The unquenchable fire of the dark side was consuming him, devouring him bit by bit. After decades of focusing and channeling its power, his body was beginning to break down.
His condition was exacerbated by the lingering effects of the orbalisk armor that had been killing him even as it gifted him with incredible strength and speed.
The parasites had pushed his body well beyond its natural limits, aging him prematurely and intensifying the degeneration wrought by the power of the dark side. The orbalisks were gone now, but their damage could not be undone.
The first outward manifestations of his failing health had been subtle: his eyes had become sunken and drawn, his skin a touch more pale and pockmarked than was normal for his age. The last year, however, had seen more pronounced deterioration, culminating with the involuntary tremor that seized his left hand with increasing frequency.

---

His lightsaber still flickered with blinding speed as he performed his martial drills, yet it was the merest fraction slower than it had once been.
The aging process was subtle, but inescapable. Bane accepted this; what he lost in strength and speed he could easily compensate for with wisdom, knowledge, and experience. But it was not age that was to blame for the involuntary tremor that sometimes afflicted his left hand.

---

A decade earlier he would have eagerly engaged them in physical combat, his body pumped full of adrenaline released by the orbalisks that had covered his flesh. Swept up in a mindless rage, he would have carved a bloody swath through their numbers, hacking and slashing at his helpless enemies while relying on the impenetrable shells of the orbalisks to protect him from their blows.
But the orbalisks were gone now. He was no longer invulnerable to physical attacks, yet he was also no longer a slave to the primal bloodlust that used to overwhelm him. Free from the parasitic infestation, he was able to dispatch his enemies using the Force rather than relying solely on brute strength.

Numbers = threat:

The remaining enemies were potentially more dangerous: the priests of Andeddu had no doubt ascended to their positions because of their affinity for the Force. Their training was probably limited, and Bane knew no single one among them was powerful enough to stop him. Together, though, they might have the potential to overwhelm him. However, he didn't intend to give them time to organize so they could attempt to unite their strength.

Unpredictability = speed:

Zannah expected Bane to come at her aggressively, but even so she was caught off guard by the ferociousness of his attack.
He opened with a series of two-handed overhead chops, using his great height to bring his blade hacking down at her from above. She easily blocked each blow, but the momentum of the crushing impact caused her to stagger back, throwing her off balance.
She recovered quickly, however, spinning out of the way when he followed up with a low, looping swipe meant to hew her off at the knees. She retaliated with a quick jab with the tip of one of her blades toward Bane's face, but he ducked his head to the side and came back with a wide-arcing, single-handed slash at chest level.
Zannah intercepted his blade with one of her own, angling her weapon so that the momentum of Bane's attack was redirected downward, sending the tip of his lightsaber into the dirt. This should have exposed him to a counterthrust, but he was already reacting to her move, driving his entire body forward into Zannah's before she could bring her weapon up.
His weight slammed into her, knocking her back as Bane snapped his neck forward. Zannah threw her head back just in time, and the head-butt that would have smashed her face glanced off her chin instead.
He was faster than she could ever have imagined, and he was using new sequences and unfamiliar moves he had never revealed during their practice sessions. But somehow she had survived the initial flurry, and now she knew what to expect.

---

Zannah had fought him once before, back when he was still encased in his orbalisk armor. She remembered it had been like battling a force of nature: the chitinous parasites covering his entire body had been impervious to lightsaber attacks, allowing him to attack with pure animal rage. She had survived that encounter only by convincing Bane she hadn't betrayed him, and in the end he had let her live.
His style back then had been brutish and simple, though undeniably effective. Now, however, his technique was more advanced. Unable to simply bully his way heedlessly forward, he had developed an unpredictable, seemingly random style. Each time she thought she could anticipate where the next attack was coming from, he changed tactics, disrupting the rhythm of the battle and causing her to give ground.

- Darth Bane: Dynasty of Evil