Nephthys
The Gr8est!!!!!!!!
Its actually told from Anakin's perspective:
Anakin skidded to a stop.
Within the public office of the Supreme Chancellor of the Galactic Republic, a last Jedi Master battled alone, blade-to-blade, against a living shadow.
Sinking into Vaapad, Mace Windu fought for his life.
More than his life: each whirl of blade and whipcrack of lightning was a strike in defense of democracy, of justice and peace, of the rights of ordinary beings to live their own lives in their own ways.
He was fighting for the Republic that he loved.
Vaapad, the seventh form of lightsaber combat, takes its name from a notoriously dangerous predator native to the moons of Sarapin: a vaapad attacks its prey with whipping strikes of its blindingly fast tentacles. Most have at least seven. It is not uncommon for them to have as many as twelve; the largest ever killed had twenty-three. With a vaapad, one never knew how many tentacles it had until it was dead: they move too fast to count. Almost too fast to see. So did Mace's blade.
Vaapad is as aggressive and powerful as its namesake, but its power comes at great risk: immersion in Vaapad opens the gates that restrain one's inner darkness. To use Vaapad, a Jedi must allow himself to enjoy the fight; he must give himself over to the thrill of battle. The rush of winning. Vaapad is a path that leads through the penumbra of the dark side.
Mace Windu created this style, and he was its only living master.
This was Vaapad's ultimate test.
Anakin blinked and rubbed his eyes again. Maybe he was still a bit flash-blind-the Korun Master seemed to be fading in and out of existence, half swallowed by a thickening black haze in which danced a meter-long bar of sunfire. Mace pressed back the darkness with a relentless straight-ahead march; his own blade, that distinctive amethyst blaze that had been the final sight of so many evil beings across the galaxy, made a haze of its own: an oblate sphere of purple fire within which there seemed to be dozens of swords slashing in all directions at once.
The shadow he fought, that blur of speed-could that be Palpatine?
Their blades flared and flashed, crashing together with bursts of fire, weaving nets of killing energy in exchanges so fast that Anakin could not truly see them-But he could feel them in the Force.'
Note that the narration only says that he's 'Almost too fast to see.' whereas Grievous literally is too fast to see. And it only says it 'seemed' there was dozens at once.