Yeah, if you notice, when you kill the lavos spawns the shell gets destroyed too..... except for one, which you need to (SPOILER)push into the right spot so you can climb it and use the chrono trigger. Anyway, why can't he be both the outer shell AND the inner being? Remember, he's an alien, he doesn't have to conform to our preconcieved notions of what a life form is. Lavos isn't even necesarily a he. How could a male reproduce alone?