Joshua's fights were inevitably solitary.
While describing it as such was incomprehensible and appear pretentious, such was the truth—Joshua could hardly work together with others in combat, or more precisely, it was when he was alone that he and his allies could unleash their full power.
There was a simple reason for that: powerful gravity affects both allies and enemies indiscriminately, or it could be said that the closer they were, the easier would Joshua's allies be affected by his gravity.
As long as Joshua was present amongst a crowd, every single offensive would be absorbed unto his body—even light would deviate in trajectory and be unable strike any of its targets. He simply could not fight alongside others, and the more allies were around him, the more he would affect them.
On the other hand, the more enemies there were, the easier it was for Joshua to fight, just like a fish returned to water.