The phantom viper wants to fight Soverick. Soverick is the champion of the furry just as it is the champion of the Vipers. If it wins the fight, then it will be able to regain some of the honor that the Paragons lost. But it also has to protect the other Vipers. Because if it doesn't, they will die and the Vipers will surely lose this battle. That will be bad no matter how much honor it manages to regain.
The Phantom Viper is able to maintain the defensive barrier that protects the normal Vipers but it has to be close to them for the barrier to remain standing. The barrier he created surrounds the 100,000 vipers in a dome instead of separating them from the arena entirely like the defense paragon did. It is to conserve power.