The beast roared in outrage, swinging it's tail right at Evis. Putting on a burst of strength, he jumped back but it wasn't enough. His ankle was grazed and he lost his balance. Luckily he landed in a crouching position with a soft "thump" or else his life might have ended right there underneath approximately 2 tons of claw, muscle and scales. And that was just it's leg.
Rather than jumping back, Evis propelled himself forward, he didn't want to be too far away or else the Genra would use it's freezing breath. It was a good thing wyverns only have 2 legs, the gigantic claws could have killed him if they weren't on the wings. He cast quick strength burst and then stabbed the wyvern in the stomach with both swords, with enough piercing force to break boulders. It screeched in pain and swung it's gigantic clawed wing in a sweeping motion.
"Shit." Evis did not want to get slashed by claws longer than his arm. He dashed to the side, switching into a roll just in time. The gigantic curved blades of bone barely missed him, lightly brushing him instead with the leathery wings. His leg had a shallow cut from one of the sharp rocks dotting the cave floor, but it only stung and he wasn't dead. But now the wyvern was facing away from him, the momentum of the swing had moved it off-center. It feebly swung it's tail at him again, only succeeding to crush a few rocks into powder.
Taking the chance, Evis enchanted his legs again with a huge burst of strength, propelling himself off the side of a wall like a rocket. His swords landed neatly in the monster's back, soaking his swords and clothing in blood and gore. Hopefully wyvern guts were easy to wash off. The wyvern howled in agony, swinging itself in all directions trying to get Evis off. But he only dug his swords in harder and waited it out. When it tried to crush him against a boulder, he suddenly sprung into action. He jumped off again and propelled himself off the boulder, this time aiming straight for the beast's head. The last thing the Genra saw was the sight of a gleaming, crimson blade gouging out it's eyeballs. It flopped to the ground, probably dead. Just to make sure, Evis walked back up to it and stabbed it's head a few times until he was sure that the brains were ready to be made into a pincushion.
"...Now to get this back to HQ." He stared at the dead corpse that was over 10 times larger than him. Maybe he should have taken a B rank instead.