i know you cant rely on google, or any web site for that matter, to give reliable information. but you can at least get ideas and see what people here think. im sure people have successfully kept eels with lionfish, its just the lionfish may have passed by the eels cove slowly while the eel was waiting for food. if kept very well fed(and not feeding live fish) you would probably be ok. you could get two of the same eels and one could be more aggressive than the other, its all about the personality of that individual fish. i have seen guppies take out other guppies because for some reason or another it didnt like the others. goldfish of all fish can be aggressive and eat anything that fits in their mouth! i dont rely on google for info at all, only suggestions for what info im looking for, but i still do my research