Mage's Tiff:
The term ‘Mage's Tiff' refers to a magical duel between two thaumaturges. Typically containing a fusion of magic and hand to hand combat. Popular in the 1800's as a way to resolve disputes, the tradition has mostly faded over time, due to the advent of modern warfare. Thaumaturgy being easily bested by a skilled marksman. Occasionally they occur in situations where neither thaumaturge has conventional arms, but it is still a rarity.

- Excerpt from ‘The History of Thaumaturgical Combat in the 19th century', by Ava Blackthorn.

“Operative ‘Transit', requesting backup. I'm withou-”
The man cut himself off, attempting to still himself as he heard distant screaming. Stuck in some cultist's base, split away from the rest of his team, no rifle, and no sidearm. Just a combat knife, and a prayer his squadmates were doing better than him. Bad decision, really, to pray right now. Wrong God might hear. The operative tried to instead focus on the actual objective: get rid of the anomalous influence in the area, including the cultists. Preferably dead, as was the GOC way.
He peaked the corner: another dilapidated warehouse- aisles pushed to the sides to make room for the pulsing forms of greenery and plantlife. Almost tumour-like, the way they clung to the metal-lined walls and ceiling. The trunk of a tree impaled the middle of the room, red fruit hanging from it. Minimal light. One hostile, doing something with said tree. Wooden staff, no firearms.
Fellow Blue.
Shit.
Transit ducked back outside, cursing himself, hoping she hadn't seen him. Sure, Grey Suits were useful, but pointless with quick movement, and as a Blue, the hostile didn't just rely on bog-standard vision. He shook his thoughts off. No point worrying now, and internally he ran through a couple options. Guns were out- couldn't just sneak some fire and be done with it. He had his knife, his blood, and the luck of being a mage. He was still going to enter and try to eliminate the target- why wouldn't he? Sneak into some random warehouse in Italy, quietly deal with some nutters trying to bring back forgotten gods. Stop a (possible) end of the world, or die trying. Completely normal career path, right there.
He breathed in deeply, an attempt to cool off. He may have to chance the Grey Suit- and hope the mage was inexperienced enough to not differentiate EVE. Backwater cultists didn't have a full grasp on Thaumaturgy. That assumption was what he had to rely on.
He moved slowly- letting the chameleon cloth adapt before he had to take another step. Footing as light as he could keep it, sticking to the edge of her presumed vision. He held his blade loosely in his left, pulling back the sleeve of his right. Blood wasn't the best source- and he'd fuck himself over if it was a sustained conflict with the amount he'd loose, and with a small patch of skin unobscured, there was a chance she could see him in the dim light. If he failed, he needed to react quickly.
Transit was barely a short sprint away from her now. Up close he could see the discolouration in her skin- the green hues beneath the pale surface. Where her eyes were supposed to be, flowers blossomed.
Her eyes.
She was looking at him.
The wooden staff was flung down in a near instant, a large green serpent lunging from where wood used to be. It reared up, striking down upon his shoulder as he crashed into it. All the glass within the room was reduced to dust. Transit instinctually slid the knife up at its neck- flesh splintering more like wood than meat, sap splashing upon his hand. Loose weave. Easy to overwrite.
In a smooth association between forms, the snake was torn away, and he struck out a spool of razor wire. Travelling a few feet before impact. Tearing a crevice into the woman's abdomen, cutting through both her wool dress, and Transit's own gloves. Leather shred as easily as paper. Gritting his teeth, he hung onto the metal with his right hand and pulled back- slamming the cultist down into the concrete flooring. Ignoring the sound of flesh rending, and more on getting the upper hand, he wiggled the wire free. Eyes on the prize: still had to do something about the plant gunk.
Transit backed up, attempting to get a handle on his impromptu weapon. He gave an experimental slash at the main woody structure, but barely grazed it- moss, then bark quickly covering the thin wound. Not good. His pondering on what to do next was interrupted by a vine nearly impaling him, springing from the wound he created. Thank God for chameleon cloth. He swung his gaze round- the briefing didn't mention sentient fucking plants. Transit's vision rested upon the women.
Who was now standing.
Who's torn apart stomach was now a patchwork of tumorous plant growth.
He flung out his left hand, combat knife sweeping along his own arm, then the plantlife beside him- blood staining greenery. A simple switch in liquid, a connection between part and whole.
Bleach seared the new wound in both the vines, and the woman. She doubled over, acacia plants sprouting from her wounds, and Transit rushed her. Several of the fruits spontaneously transformed into grenades, causing a cascade of explosions and falling branches behind him. Some flesh went with the razor wire as it was chucked at her- wound metal turning to the blade of a circular saw. He grit his teeth at the sound of bone being ground clean through. A second later, the firm leather of his boots crunched into her ribs. They were sent sprawling into the ground. He re-angled his knife, bleach still thick on the blade, and struck her shoulder. He was aiming for the neck.
But the acacia tree growing into him was rather distracting. He screamed.
Transit wrenched himself away, but the branch already skewered his right arm, drilling into his bones. The struggle just wound him deeper, and the cultist had noticed this. There was a sharp jolt of pain as his head was slammed into the floor, the rest of him following. He kicked blindly, hitting the saw, embedding it deeper into her torso. It snapped: shards puncturing organs and plants. He writhed haphazardly. More of the saplings were sprouting, shredding the chameleon cloth around his neck.
He twisted the knife out her shoulder. His own lips were bloody from biting away the pain. Thin strips of sapling tore grooves along his neck. The cultist was still pinning him down- but her grasp was weaker. She was burning herself out with her own magic. He pressed the knife into the woody sections of her form- no longer to wound- but to get some leverage. With a good thrust, Transit forced her off him, branches breaking off her skin. He rolled himself over, scrambling to get some distance before he cast a last-ditch spell. The cultist clawed at his heel as she attempted to pin him back down again, which earned a square kick to the face. Cartilage crunched under the blow. His arm and neck were painfully numb, and soaked to the bone with blood.
The mage heaved himself up. He had… an idea. Blood and fire were both the same thing, really. Both hurt, both healed. Transit slid the combat knife against his own arm, much like one would strike a match. Blood coated the edge, and he tried to not think about how much of the precious liquid he was losing.
In a swift motion, he flung the blade back at her, the metal and carbon polymer exploding into a fiery mass, lit by a fuse of gore. He was thrown back from the sheer force- and thank god. The other mage wasn't so lucky- fleshed rendered as she was impaled upon the crumpled metal of the warehouse, greenery immolating in a blaze of glory, as it grew even higher. Wood splintered the frame of the building, before the blaze overtook it further. The operative watched, bleary eyed, and the woman caught on fire too. The smell of charcoal hung heavy as hair, then flesh, then bone burned. Transit collapsed, distant yelling drowned by the crackling of flame.

“So— what happened after I got knocked out?” He glanced at his squadmate, while failing to light his cigarette with one hand, the other still in a sling. A more long lasting reminder to not try to rush in alone when dealing with a rival thaumaturge.
Clearly fed up with Transit's struggle, his colleague grabbed the cigg, lit it, then passed it back up. “The fire speed. Burned the whole thing to the ground.” They gave him a short glare, a response to the oddly smug grin the former operative had. ICSUT brats, and their love of dramatics.
Despite the response, the smug grin remained. “Yeah, yeah- the parathreat? The cultists?”
“Your eardrums get damaged too Transit? Burnt to the ground. If anyone has survived, they'll be lying low for a long while.” A cuff on said ear was awarded for the continued apparent joy. He'd never learn to be more careful if all he got was bragging rights. “And don't take it to heart. You pulled a stunt, and got lucky. Next time you'll get pinned by a mage more skilled than a third grader.”
“Cruel. I just immolated-”
They sighed, cutting him off. An operative gets chucked in a Strike Team, and they act like they own the world. “And I don't want to hear about it. You're a dime-a-dozen Thaumaturge, who nearly got himself killed, and…”
They paused looking at Transits' kicked-puppy-dog expression.
“…It was mildly impressive to watch the results.”