Yang Song had not joined the battle yet, so he had time to think about various things. Among all the things, he was keenly aware that the boss had not appeared yet.
The abyssal demon boss that appeared last time was quite strong enough, so Yang Song estimated that the boss this time would be stronger or just more in number.
Although there were many Grandmasters here, they were busy fighting with the other abyssal demons after all. Hence, by the time the bosses came, Yang Song estimated that they would not be full in energy at all.
Actually, with Yang Song's strength, he could hide somewhere and just let everyone else deal with it. But it was not the best way after all. In addition, as an immortal cultivator, the more good deeds he did, the more likely that he would not be bound with the dark side of the "cause and effect".