carthage
PLEASE PROTECT ME STONES
Lightsaber combat
In terms of lightsaber skill Mace is undoubtedly Malgus's superior with accolades calling him second only to Yoda, a champion of the Jedi order, and one of the greatest Swordsmen produced by the Jedi order. He's defeated Asajj Ventress, fought evenly with General Grievous, was reputed to be Dooku's equal on neutral ground, stomped Quinlan Vos, fought evenly with Sora Bulq, along with his accolades that logically place him above Malgus. He'd take any duel with effort on his part.
Force abilities
While Windu is a greater duelist than Malgus, the area of their force abilities is where the greatest disparity lies. Mace Windu has telekinetically destroyed bridges, destroyed battle droids, moved massive doors, used shatterpoint to shatter glass, used force crush on General Grievous. Yet with any of his higher end telekinetic showings he's always required a great deal of effort in comparison to Malgus:
Windu required a great deal of concentration to push this Clone walker off a cliff
Windu struggled to lift a large chunk of metal in R2 Come Home (11:30)
https://www.youtube.com/watch?v=dVrBJDIjODY
Mace also found himself unable to lift a train in Shatterpoint, believing that to be something only Yoda was capable of.
In comparison to Malgus who can telekinetically the tons of rubble two buildings (described as an avalanche of duracreet and transparisteel) and blast them away with telekinesis wrecking other buildings in the process decades before his prime in this thread:
Malgus stood in a pocket under a mountain of rubble, legs bent, the power from his upraised hands preventing several tons of duracrete and steel from crushing him. Dust made his already troubled breathing more difficult. He coughed as the words of his father echoed in his mind.He'd been sloppy, so lost in his need for revenge that he'd failed to properly evaluate the Jedi's power. He'd surrendered his reason to bloodlust. But no more. With an effort of will, he contained his anger, controlled it, made it a whetstone against which he sharpened his power. Using the Force, he blew the rubble up and away from him. It fell with a crash into the adjacent buildings. A Force-augmented leap carried him out and over the heap. The Jedi's eyes widened as Malgus hit the street. Malgus sneered and charged.
Malgus's lightning likewise was capable of overcoming that same Jedi's defenses and burning black holes into his skin:
At 10 meters, Malgus extended his free hand and loosed veins of blue Force lightning. They struck the charging Jedi: swept through his defenses, swirled around him, and began to burn flesh.Shouting with pain, the Jedi leaned forward into the lightning - teeth bare, blue blades held before him - and staggered toward Malgus. Despite his burns, he came onward. One step, another, another, but he was failing, wilting in the heat of the lightning. Malgus channeled more power and the Jedi fell to his knees, screaming. The lightning spiraled around the Zabrak, blasting dark holes in his body. The lightsabers fell from his hands and he writhed in agony, screaming his pain into the sky
Malgus's lightning has also blown through the defenses of Lord Adraas and Aryn Leneer.
Malgus held forth his hand and the rage within him manifested in blue veins of lightning that discharged from his fingertips and slammed into Adraas. The power stopped Adraas's charge cold, blew his lightsaber from his hand, caught him up in a cage of burning lightning. He screamed, squirming in frustration and pain."End it, Malgus! End it!"
-Deceived
As Aryn prepared to leap at Malgus, he held forth a hand, almost casually, and lightning sizzled through the space between them. Aryn interposed her lightsabers, but the power in the lightning exceeded anything she had felt from Malgus before. It blasted through her defenses and both lightsabers flew from her hands. The lightning seized her, lifted her up, and threw her from the top of the shuttle.As she flew toward the deck, she smelled burning flesh, heard screaming, realized that it was her flesh, her screams. She hit the ground hard and her head bounced off the ground. Sparks erupted in her brain, pain, and everything went dark.
Its worth noting that Leneer can use barrier/deflection to cushion the impact of a telekinetic blast, deflect a telekinetic blast that can topple statues, and use force shield to stop the impact of terminal velocity while falling from a ship.
Yet Malgus was still capable of blasting her across a hangar in their final duel:
Malgus bounced up from the somersault and loosed a telekinetic blast that lifted Aryn from her feet and blew her across the hangar.
-Deceived
Most importantly Malgus's showings as of the False Emperor flashpoint where he telekinetically blasts/chokes, and downs the protags with lightning:
(The characters composing the flashpoint called the Republic/Empire's most powerful heroes)
http://www.swtor.com/holonet/flashpoints/false-emperor
-Scans/Quotes courtesy of Shootingnova/Sunrazer
It stands to reason that once Malgus starts to lose a lightsaber duel, his force abilities in lightning and telekinesis will immediately be a game changer in the match. Windu at his best struggles to lift a single chunk of metal and knock down a Clone walker down a short distance from a cliff's edge, in comparison to Malgus who can blast away the rubble of two buildings (decades before his prime), blast away/choke the Empire/Republic protags, and overpower the barriers/defenses of Aryn Leneer/a Jedi that can collapse buildings would overpower Windu if not swing the match in his favor. While Windu enjoys a skill edge, Malgus can hold his own (as Saesee Tiin/Republic-comics era Ventress) and ultimately close the deal with his vastly superior telekinesis and his raw power advantage.