Who is the Grandest Magus?

The Invoker strode down the lane, the denizens of the Dire's lands scurrying after him, chittering and chattering in their own strange tongue. When they bumped into his back he glared back at them with murder in his Exort-charged eyes. They backed off slightly when he did, slowing their progress. Eventually they realized that they could walk around him and sprinted past him, swords held aloft. They charged into battle with their Radiant counterparts, all leaves and flowers where the Dire was bone and rock, and the Invoker set about his harvest.
He raised his hands and gestured to the air thrice, murmuring “Exort” with each motion. Three orange spheres of flame orbited him, empowering him to destroy. One of the Radiant creeps stumbled back, heavily wounded, and the Invoker threw a small bolt of blue-white-orange fire at him. The thing was thrown back bodily as the projectile smashed into it, and Invoker heard the tinkling of gold, somewhere.
“Insipid,” He spat, and smashed one of the Dire's creeps into oblivion with another well-timed shot. “All things fall, little one,” His voice boomed, as energy poured through him. On and on this process went, with no signs of an adversary, until suddenly...
He was about to repeat the killing again when a green bolt of magic ricocheted between his creeps, cutting them down like chaff, and earthed itself in his body. He grunted in pain and fell back, cursing his luck that he would be put against such an enemy.
He saw the gleaming, glossy black of his opponent's facemask and the coruscating green of his energy. The Invoker spat an imprecation and conjured three blue spheres of ice and cold. He called and invocation up from the bottom of his mind and threw it at the newcomer.
“Sadron's Protracted Frisson!”, He hollered, and grinned when his opponent's movements stuttered into nothing over and over again. He dived after his foe, slinging shot after shot of fire at him, when his foe suddenly span, giggled like a madman and raised a hand.
“Up!” Yelled the other sorceror, his cape whipping in the arcane winds, “And down!”
The Invoker was seized bodily and thrown up into the air, suspended and slammed down, dazed, among his creeps. The opposing thaumaturgist laughed again and snatched something invisible from the air, and Invoker saw a green streak of light leave him and fly towards the wizard.
“I wonder how this one works?” Mused the magician, before clicking his fingers.
To Invoker's horror, his limbs seized and his body refused to work as his own incantation was turned on him. He tried to move and succeeded for a brief moment, before another strike hit him and he was frozen again. He turned and threw shots of his own back at his attacker, dealing, as he saw, substantial damage. He threw his hands up and yelled another incantation.
“Wex Quas Wex!”
A tornado of ice and lightning whipped from his hands to smash the opposing wizard from his feet and hurl him up in the air, almost killing him.
“I think not!” Yelled the masked wizard, and snatched again at the Invoker. He clambered to his feet, leaning heavily on his staff. “Oh, so that's how it's done...”
A tornado equal to the Invoker's lashed out and threw him from his feet, and the masked Magus advanced upon him. The Invoker could not force himself back to his feet, his strength having been destroyed in the engagement. He lifted an arm shakily, flashes of purple and blue light flickering around his fingers.
“W-Wex... Quas...”
The masked sorceror prepared a spell in his hand and leaned down towards him.
“Poor show, Arsenal Magus. Remember this mask.”
“Curse you, Mimic Magus...”
Rubick, the Grand Magus, unleashed a bolt of pure power into the Invoker's chest, watching with satisfaction as the immortal's body burned away in the triple-hued colours of his arcanery.
The Grand Magus glanced up and hopped to his feet, dancing about hyperactively.
“F-F-F-First blood! What is this? I came here to b-be tested!”
However, Rubick knew he was severely injured and hobbled back towards the Radiant fountain, hoping he could get there safely.


Meanwhile, the Invoker sprang forth from the Dire, full of vengeful power. He summoned the three spheres of Exort again and invoked one of his favorite spells.
He searched with his mind through the battlefield and pinpointed a point in his thoughts. The sun span quicker on its axis and stood stock-still as a single point of light lanced down to hit the battlefield.
What's that noise? Wondered Rubick as he crossed the threshold into the Radiant's stronghold. It sounded almost like...
HARLEK'S INCANTATION OF INCINERATION!
The Invoker's triumphant proclamation rung out across the battlefield as the sun's fury smote the Grand Magus into a thousand little cinders, leaving him nothing but a pair of boots and a staff.
“Learn to respect your elders, little wizard...” Spat the Invoker, and strode once more into battle.