My cat died... (Sort-of...)?

So, here's what happened. I was outside playing with my kitty-cat named Felix, and then he ran across the street, but on the way he got hit my a truck. He died... I was emotionally destroyed. He meant everything to me... He was my best friend... So I followed an ancient ritual I found on Google and followed it step-by-step to resurrect him. He's back now, but there's one problem... since I brought him back, FELIX IS A BLOOD THIRSTY KILLING MACHINE!!! WHAT DO I DO????