The Young Lord squinted his eyes as he did not really have any means to force Ying to follow him. If he tried to force Ying, he and his faction would be expelled from the city. With the ongoing situations, they would be an easy target for the other factions. They wanted the Dragon's bloodline and were aware of that, so getting expelled from the city was the worst possible outcome for the Mistovel Family. There was no loophole where he could force Ying to obey the council aside from the empty threats.
"Your defiant attitude just makes you more suspicious, Ying. If you refuse to give a testimony, then the alliance will put you on a wanted list. You will have the honor of being the first person to enter the wanted list." The Young Lord added. However, that was just a weak argument in Tang Shaoyang's eyes, not convincing enough and not threatening enough.