Anywhos, viruses and bacteria are a form of cellular organisms so obviously they can evolve to a multicellular state like animals have. Likewise, I state this.
Actually viruses are neither cellular nor organisms, which means they're technically not "living" things at all.
Scientists still debate this, but current consensus would agree to that statement. However, viruses DO still mutate and become more
deadly efficient. One could say that viruses are the direct physical manifestation of evil, being difficult to eliminate and purposed only to perpetuate themselves at the cost of the host.
Regardless, life exists now where once there was none, this is true no matter which you believe, evolution, god, or any mix of the two.
Since CT uses evolution, it stands to reason that a virus strain, over billions of years, became capable of being classified as life... or perhaps Lavos is not a living thing at all... Biological maybe, but not living. Perhaps that is what allows it to exist in the pocket dimension in the first place. As for forcing the Entity do things against its nature... why not? Viruses do the same to us. They vandalize our DNA one cell at a time, reproducing themselves indefinitely until we die or they are eradicated. We have no more control over what our individual cells do than the entity has over what people do.
Here is the root of the problem with life though: Life cannot be quantified. It cannot be defined, created, or directly studied. It can only be left alone, or forcibly removed. You can attach words to it that try to define it... but in the end, we don't know what life even is.
One could say that life is something that acts with a will, to accomplish a goal, in which case viruses would be as much alive as bacteria. But then there is the problem of 'will'.
Science generally tries not to use things it cannot understand to explain other things... unless it is an undeniable existence such as life.
What is it that makes a corpse of a child that was healthy but simply died... dead? What is it that makes a virus, which acts to accomplish a goal of reproduction... not alive?
A virus can differentiate, and direct its own movement rather than floating aimlessly... but yet it does not respond to stimulus... this is why Viruses are considered non-life, and yet still debated as possible life, because they act like both.
Regardless of living or non, I believe Lavos is the evolved state of a virus. It is the only kind of existence that reflects Lavos' nature in my mind.