C2479 The old man and the old woman

Truly calm down, the current Cheng Fei was constantly pondering over how to refine a strong toxic pill.

Generally speaking, the materials to refine toxic pill were all very complex, and all the materials that could not be refined into Pills were used to refine the toxic pill.

This was precisely the method Cheng Fei had used to concoct the Rainbow Pill.

Actually