Qin Dangtian's astral soul trembled, like it was enduring against an unlimited pressure. His Absolute Beginning Astral Soul had the power to evolve all laws, he could even absorb the attacks of others. However, when Qin Wentian's attack was so strong that it exceeded a certain limit, even if Qin Dangtian had the Absolute Beginning Astral Soul, it was still tough for him to bear the burden.
Earlier, Qin Dangtian used the Absolute Beginning Astral Soul to manifest the dimensional blackhole. He was the same as Qin Wentian and used that to absorb energy. However, his was after all not the original source and he didn't have a connection with the particular dimensional constellation. Hence, he couldn't digest it fully and could only use his Absolute Beginning Astral Soul to manifest some of the characteristics.