Jing Ji knelt before Lu Bei with a thud. A man's knees are his most valuable asset, as such, this kneeling was akin to offering a fortune.
He was very afraid of Lu Bei, literally afraid, without any extraneous emotions mixed in.
At present, the Nine Sword Elders, including the old salted fish Qin Fangtian, were also afraid of Lu Bei. The Sword Heart, Sword Intention, Sword Body, and even the nine swords they wielded sided with Lu Bei, compelling them to fear.
But their fear wasn't pure, because they were compatriots, they had some illusions about Lu Bei.
The Sect Master is simply donning the mask of fake evil; essentially, he is a good person.
This was not the case for Jing Ji. When he held full control of the Lingxiao Sword Sect, he saw Lu Bei as a critical chess piece, then as an essential collaborator, and later...
He witnessed Lu Bei's step-by-step rise, from initial admiration to later dread, understanding Lu Bei far better than the Nine Sword Elders.