RE: Is Deoxys a real Pokemon?
It depends on the definition of Pokemon. Deoxys isn't from any planet, and was born from a space virus. Therefore, it's a virus, rather than a Pokemon. However, it can use attacks, is intelligent, and has an ability. Therefore, it's a Pokemon. But there's still more. It's developed a language- granted, it's a telekinetic one, but still-, and it can transform itself to fit the situation- but it isn't pernament. In those ways, it's unique.
Virus, Pokemon, or Sentient? I leave that to you.