Louise Valierre summoning angered Vegeta in the summoning ritual, and then Vegeta killed her and destroyed her planet.

Louise Valierre had been dabbling in dark magic for many years, using it to try to gain great power. One day, she decided she was ready to try her hand at summoning a powerful being from another realm. After much strenuous preparation, she began the ritual, and summoned the powerful Vegeta from the other realm. At first, Vegeta was confused and angry about being summoned, and even more so when he learned of Louise's dark intentions. His anger slowly began to build, until it could no longer be contained. He erupted with a strong burst of anger and power, more than enough to destroy Louise and her planet. In an instant, he wiped out Louise and her planet in a single blow, leaving nothing but dust and rubble in his wake. Louise had thought she could gain power by summoning the mighty Vegeta, but instead, she had unleashed a force more powerful than she could handle. Her foolishness had cost her dearly, and the world would never be the same again.