Qin Wentian’s request for the Ouyang Aristocrat Clan and Jiang Clan to battle, was actually because of the fact that despite his current strength, he was still helpless.
Right now, although the hidden Azure Faction was already reunited, they only had Fairy Qingmei, a single Celestial Phenomenon Ascendant. Evidently, his current strength was insufficient to clash head on against a top-tier transcendent power like the Great Solar Chen Clan. If not, why would Fairy Qingmei need to wait so many years? She would have finished things long ago, if she could have.
Hence, Qin Wentian needed the strength of the alliance to deal a critical strike to the Chen Clan, making it so that once they stumbled, they would be unable to rise again.
Also, Fairy Qingmei had revealed some secrets behind the Azure Emperor’s death to Qin Wentian. Back then, the Great Solar Chen Clan were the masterminds. And if it wasn’t for her timely appearance, the Hua Clan and Wang Clan would all have acted as well.