I also got this, going against the notion that a God is above any possible changes of the cosmology:
作中で波旬が歴代神格の理を投げて攻撃してましたが、他の2~5代目の神格も前任者の技を使ったりできるんですか?
できますよ。
あの手のことが一番上手いのが五代目の黄昏。彼女の覇道共存能力がその究極系。
逆に一切できないのが四代目。彼は自分の代で神座システムを大幅に変えたので、前任者たちと相性が悪いのです。
波旬はまあ、本編でも言ったように塵投げてるようなものですね。前任者に対する理解も尊敬もまったくないので、威力だけは再現できても中身スカスカなんで文字通りの形骸です。
In the main story, Hajun threw the Laws of the previous Gods to attack, but can the second to fifth Gods also use their predecessor's techniques?
They can.
The one who is the best at that kind of thing is the fifth generation, the Twilight (黄昏/Marie). Her ability of Hadou Coexistence is its ultimate system.
Conversely, the one who can't do it at all is the Fourth Generation. He changed the Divine Throne System (神座システム) so drastically in his generation that it doesn't work well with his predecessors.
Hajun, well, as said in the main story, he's throwing them out like dust. He has no understanding or respect for his predecessors at all, so even if he can recreate their powers, its contents are hollow due to being a literal skeleton.
So Merc changed things to the point of becoming incompatible with the previous gods.
But what is the nature of this change?
「その者、特異な存在なり。これまでの座は、総て前任者の理に対する歪ひずみとして発生し、善悪の交代でしかなかった状態に終止符を打つ」
"He is a singular being, one that brought an end to the previous Thrones, which had all occurred as distortions to the reasoning of the predecessors, and were nothing more than alternations of good and evil."
男が有する特殊性の中でも最たるものは、彼の渇望が時間軸を無視していたこと。何某かの経験によって強烈な想いを抱き、そこから神域の念を発生させるという原因と結果が入れ替わっている」
"The most significant peculiarity of the man was that his craving defied the time axis, and causality was reversed: some experience gave him intense feelings, from which he generated those thoughts in the divine realm."
「すなわち、すでに神座にある己を知覚したからこそ、そこに至った。それまで単一時間、単一宇宙のみで構成されていた座の機構を、破壊し書き換えたのが彼である」
"In other words, he had reached that point because he had already perceived himself on the Throne. He is the one who destroyed and rewrote the mechanism of the Throne, which at that point consisted of only a single timeline and universe."
「現在過去未来の内包、多元的並行宇宙の同時掌握。それを成したこの男は、過去三代を上回る最大の支配領域を獲得した中興の祖と断言できる」
Simultaneously seizing the present, past and future, and multiple parallel universes (多元的並行宇宙), this man founded an era in which he has acquired the largest territory of control over the past three generations."
「簡潔に述べるならば、三代目の座にとってこの男は、別の時間軸と宇宙から飛来してきた怪物に他ならない」
"To put it simply, for the Third Throne, this man was nothing more than a monster from another timeline and universe."
「原因と結果を入れ替えたことによって発生した彼の宇宙は、歴代で類を見ないほど摩訶不思議なものと化す」
"His universe, generated by causality's flipping, is more mysterious than any other in history."
It is the introduction of the idea of multiversity, time travel and causality shenanigans in the world.
Unlike what others are claiming (often without proof), you have direct explanations of how the world changing actually is influencing Gods and the Throne A LOT, to the point of creating incompatibility between Merc and the 3 previous, who would see him as a true monster because of how he revolutionned the universe.
If Gods and Throne were naturally above all extensions regardless of what happen, none of these explanations would exist at all.