As soon as Lux gave the order, Draven and King Leoric made their move.
They were the two in charge of capturing Lucius, while the others were on standby to deal with any situation that might arise if they failed on their first attempt.
Since Draven had marked Lucius' shadow, he knew the exact location of the merchant, so they didn't hesitate to infiltrate the Merchant Guild in order to find him.
However, as someone who had offended many people in the past, Lucius made sure that his living quarters were well-protected from any kind of assassination attempt.
The merchant's personal room was actually deep underground, surrounded by many Elite Guards as well as Traps for those who would even attempt to harm his life.