Because you like Princess Bubblegum in Adventure Time
Basil Hallward is dominated, soul, brain, and power by Dorian. See them in Dorian Gray.
With her consciousness so easily shifted between bodies, Motoko Kusanagi is left unsure of who or what she really is. See them in Ghost in the Shell.
Susie Salmon has a big heart, even though it's not beating anymore. See them in The Lovely Bones.
Michael Bluth is the only sane person in a family of eccentrics. At least, that's how he thinks of himself. See them in Arrested Development.
A cursed pirate captain, Barbossa is greedy, vengeful, and surprisingly cheeky. See them in Pirates of the Caribbean: the Curse of the Black Pearl.
Donna is boisterous and spunky traveller of the TARDIS, exploring worlds beyond the simple mundane enterprises of Earth. See them in Doctor Who.
A champion of chivalry, Don Quixote is dutifully bringing good to the world—even when others think he's out of his mind. See them in Don Quixote.
James Wilson is a compassionate doctor who willingly plays the sidekick. See them in House M.D..
With an abundant supply of alcohol, nice restaurants, and free will, Crowley is a demon who is thoroughly enjoying his time on Earth. See them in Good Omens: The Nice and Accurate Prophecies of Agnes Nutter, Witch.
It's easy to see why Poe Dameron would side with the rebellion: he's bad at taking orders, likes to show off, and is committed to the cause. See them in Star Wars Series.