C622 toxicology

When he saw the bloody limbs, he realized that he had already failed. He really hadn't thought that he would fail without knowing why.

What kind of method did this person use?

"You don't understand, right?" Yang Xin sneered, and pointed to his own chest. "Your plan is not bad, you have to capture an extremely good flying sword at the very front.

The next moment, he stabbed me in the heart, but