Shiva himself did not invent it. He did invent ta'n'd'ava however. The inner motivation of ta'n'd'ava is the following: "Destruction is inevitable, but I will continue to fight against destruction through struggle." So there is a skull in one hand and a dagger in the other. The skull represents destruction, and the dagger represents fight. The underlying feeling is "I will not surrender to destruction or death. I will continue the struggle with this dagger."
