If they had just been ordinary subordinates or even internationally renowned hitmen, Lucas wouldn't be afraid.
But they were clearly suicide warriors, causing Lucas to be ill at ease.
The reason suicide warriors were called suicide warriors was that they were willing to sacrifice their lives in order to achieve their goals. They didn't care about anything else, and they had no bottom line either.
They would stop at nothing to achieve their goals.
Moreover, once suicide warriors who hid poison in their mouths were captured or in an unfavorable situation, they would immediately bite the poisonous capsule and end their own lives, making it impossible to find out who the person who ordered them was.
Lucas wasn't afraid of suicide warriors, but what about the people around him?
If suicide warriors targeted his family after failing to kill him, Cheyenne, Charlotte, Amelia, and William would have no way to deal with these people.