The green cloud around Green Viper was made entirely of acidic poison, so it was very dangerous. But not only was it dangerous on contact, Green Viper could also control it.
Green Viper manipulated the cloud and shaped it into the form of a giant green snake. His figure was now on top of the head of the giant snake, with his waist apparently fused with the head of the snake.
On the other side, Arthur threw aside the Storm of Blades. He let this artifact prepare itself and be on standby. He didn't intend to use it now because he wasn't sure that the green energy that Green Viper produced wouldn't corrode it.
He determined that his main reliance for this fight will be spells, which is why he activated the Lightning Angel spell and the Lightning Net spell.
He didn't bother to use wood spells, though. This was because he had the same concerns as the ones he had for the Storm of Blades.
