Lor'themar Theron became the Regent after the Prince embarked on his expedition to the Outland, rendering him the top leader among the High Elves.
He once served as the deputy to Sylvanas, commanding the ranger force as a senior general. After Sylvanas' death, his reputation soared within the military.
Even with the presence of the Prince, he is now the second most influential individual in the kingdom.
Hence, it was a surprise for Li Yao to see Lor'themar amongst the emissaries, which subsequently led to his realization.
It seemed like the Prince was about to lead a major expedition to the Outland, leaving the kingdom incredibly vulnerable. The High Elves might have joined the Dark Camp, but due to their arrogant nature, other races are hesitant to interact with them.