Shadow is, well, a Shadow Lugia. He wishes to completely reverse the roles of humans and Pokemon. He does this by corrupting other Pokemon with shadow energy, making them evil and forcing them to turn against their trainers. The effect varies on how much the corrupted Pokemon likes their trainer. Shadow, in general, isn't a fan of humans, but he finds them acceptable as pets, servants, playthings, or even his prey. He might even treat them fondly if they are obedient to him.