He knew that he had also dealt with the Saint Lord of Wind and Thunder, and he was even clearer that such strong opponents, if given the chance to confront other strong ones, would absolutely not miss the opportunity.
The former Saint Lord of Wind and Thunder may not have had any dealings with the Jade Emperor, and given the Jade Emperor's habitually dormant nature, even if the Saint Lord of Wind and Thunder wanted to challenge him, the Jade Emperor would not engage in battle.
But this time was different; if he was to get hold of the Great Law Decree Technique, it would be akin to seizing the Jade Emperor's lifeline, and the Jade Emperor, wanting to retrieve the Great Law Decree Technique, would certainly not avoid battle but would, on the contrary, actively engage in combat.