The ones closest to Master was John's group, but they couldn't get close to him. Master was protected by his legion of demons, zombies, and summons. They couldn't even determine his exact position when the second sun appeared above them and started burning them with heat. Much less defeating Master to complete their objective, they needed to attack Master to stop him from sustaining the second sun. Or else, that sun would burn them to death.
It was easier said than done. Master was already a summoner who could summon more minions than most before he became a God. After he became one, his hacking gave him even more non-standard summoning spells. Combined with the legion he called using the Mass Recall Plate, the overwhelming number of enemies made approaching Master seem impossible.
