The Five Tiger Killing is derive from TaiSui (太歲). Harm and Hurt is said to come from the Five Tiger Killings. The effect is seen to be manifest at a greater volume if the afflicted sector is injure by external landform (i.e poison arrow and road clash).
The Five Tiger (五虎):
Depending on TaiSui, in the month of February there will be a BAZI pillar, use the heaven stem and start counting till 戊，己. That would be the Five Tiger Killings. The Earth Tiger is said to be worst off because 戊，己 will appear 2X.