((ooh...this should be fun. Okay. You didn't specify what sort of sorcery they employed, so I'll assume it's multi-elemental.))
V'kleta grinned at the thought of battle with these mages. These close confines are perfect for the assassin-breed form he's been waiting to use. First, he rushes forward at the first mage, the one in the center, who is weaving his hands in a complex pattern and muttering a spell. V'kleta morphs heavy goatlike satyr legs, and does a backflip-kick that knocks the mages back, interrupting the one's spell and allowing V'kleta the short time he needs to transform.
V'kleta stands with his arms spread wide and crouches, bowing his head as energy crackles over him. His clothes melt away into nothingness, save a jewel-encrusted belt and an ornately-decorated loincloth. Arcane tattoos appear, covering his back and upper arms. Thick horns rise from his elbows, back, and the rear-facing knees. The fur of the Satyr legs disappears, replaced by hard reptilian scales. The hooves are replaced with the talons of a primordial dinosaur. His fingers grow wicked claws, and small, hooked claws grow from his ribcage. His eyes turn yellow and reptilian, and a long, serpentine tail ridged with flat spines and tipped with nastly-looking blades grows from his rear end. To complete the transformation, two demonic horns sprout from his forehead and curve proudly forward. He looks up with a grin, arms still spread, and beckons the mage to come to him.
The enemy sorceror growls appreciation of V'kleta's shapeshifting ability, obviously recognizing the power required, but is not intimidated, and he throws his hands forward, shooting a bolt of electricity at the new V'kleta. As the energy arcs towards him, V'kleta grins and leaps, not at the mage, but straight up. Flipping midair, he lands on the ceiling and waggles his tongue at the infuriated mage. He darts along the ceiling with lightning speed, weaving to avoid the scorching blasts of electric energy the mage throws at him in quick succession. The smoke generated by the blasts temporarily clouds the mage's vision, and he stands in a ready position, eyeing the fumes where he last saw V'kleta. Behind him, a dimly visible shape drops silently to the ground behind the sorceror, and the spiked tail whips out of the smoke to smack the mage in the back with the blunt end, driving him forward and making him angrier. He turns to face his attacker, and V'kleta crouches and breathes in deeply. The smoke in the corridor swirls around him and sinks into his body, and the hall is once more clear. The mage yells and runs forward, delivering a hail of blows upon the elusive but now-stationary V'kleta, who bends and yields to each hit, welcoming it. The mage's punches carry elemental power, resulting in a frostbitten patch on V'kleta's chest, a slightly burnt portion of his ribcage, and a gangrenous bruise in his stomach. The sorceror delivers a final kick to V'kleta's jaw, and V'kleta falls back to the ground.
The sorceror, thinking he smells victory, arrogantly steps forward to kick the prone figure. As he raises his foot, V'kleta's mouth turns in a smile, and the mage's face goes white as V'kleta's tail whips out to deprive the man of the foot still on the ground. Now very much in pain and very very angry, the sorceror falls to the ground and suddenly finds V'kleta directly on top of him, slashing and kicking and gouging with his horns. Within seconds the battle has turned and the mage is merely attempting to escape with his life...but V'kleta has decided that the man's life is something he wants, and V'kleta gets what V'kleta wants.
The mage slams his hands into V'kleta's chest, releasing elemental power into the barrel of the demon, and V'kleta flies up into the air, but flips and returns to the ceiling. He races along the ceiling, to the walls, to the floor again and stands behind the still-getting-up sorceror. V'kleta grasps the mage by the nape of the neck, and his tail flashes once,then twice, and the sorceror's arms fall to the floor, dousing the stone with blood. V'kleta turns the man to face him, and the mage manages a final scream of anger and pain before V'kleta's jaws crunch into his face, silencing him forever.
((See, he doesn't need a big form to kick ass. Did I do the mage justice enough? I gave as much advantage as I could while still allowing V'kleta to dominate the battle, as is his nature.))
((Edit: Wow. That is a lot longer than it looked in the "quick reply" box...sorry for that. I got carried away. I'm a budding author.
))