Other than the meeting that he had with the entirety of the Heavenly Strength Society, the Heavenly Demon additionally had an enclosed one between him and the Four Pillars…
Just like he said before he went out with style, he mentioned that something wrong could happen. The fact that the invasion that could take centuries before occurring had come about in his era could be considered as ominous as it was a very rare experience, so it was normal to expect that things wouldn't go smoothly.
However, even when they were told to take the probability into account, the Four Pillars were still stunned by the Heavenly Demon's death!
Within the four of them, two had entered the Society alongside him, being from the same generation, and another was his junior with whom he kept a good relationship. Other than the Absolute Spear who was a maverick unattached to generations, the rest were closely tied to him.