Stephenie Meyer heroines have a thing for statuesque marble men. Jared and Ian are basically Jacob and Edward from the Twilight series. Jared is all testosterone, fury, and aggressive kisses like Jacob. Ian, like Edward, is a marble Adonis: sympathetic and caring, and more than a little controlling.
And did we mention handsome? We know he's hot because of his studly, classical nose: "his nose was perfect [...] the kind of nose that I'd seen in pictures of famous sculptures." (18.83) This comparison is important because works of art are Wanda's main frame of reference when it comes to beauty. She's an alien, with no basic concept of what humans find attractive.
Well, he wishes he had the alien parasite living inside of Jared's girl. Write that song and get back to us, Rick Springfield.
But it doesn't start this way. At first, Ian's right alongside Jared in wanting Wanderer/Melanie dead. He even calls her a "tricky bugger" (16.11). (Or maybe he's just showing his love for Orson Scott Card's Ender's Game.) But he soon realizes that even though Wanderer is an alien, she has a kind and compassionate heart. Or something like a heart, anyway.
Like all of Wanda/Melanie's relationships, this one is complicated. Wanda feels jealous of Melanie, because it's her body that Ian finds attractive. Melanie hates Ian, and doesn't want him touching her. In fact, "Melanie wanted to hit him" (38.107). Oh, the melodrama of being trapped inside someone else's body. Even soaps haven't gone there (we think. You do the research yourself.)
In the end, Ian proves that he loves Wanda as she is. He assists in her transfer from one body to another, saying "I held you in my hand, Wanderer. And you were so beautiful" (59.98). However, we can't help but think that appearance still plays a big part in his attraction. Wanda is put into the body of a cute, sixteen-year-old girl.
(Talk amongst yourself about the age gap. Ian is in his late twenties. We'll just point out that Meyer has a thing for age gaps.)
Would Ian have loved Wanda just the same had they put her into Bill Murray's body? Then again, even we humans can't help the body we're born into. How much of an impact does physical attraction play on a relationship?
Perhaps we're a little more inclined to be Team Ian since he's not a total jerk for most of the book the way Jared is, but Ian still has his issues. The closer he gets to Wanda, the more he subtly wants to control her. When Ian tells Jared "[Wanda's] a person, Jared, not a tool" (46.97), it may sound like he's defending her. To us, it seems like he just wants to control her in his own way.
See, it's all part of the fight for Melanie's body. Both Jared and Ian want it for different reasons, but Jared is the one who ends up giving Wanda/Melanie a little more freedom—letting her injure herself during her plot to deceive the Healers, for instance. Ian, however, just wants to shield her from everything: "Someone has to protect her from herself" (46.118).
Ian's control issues make the ending a little more troubling for Wanda. When she gets put into another body, she no longer has Melanie's strength and athleticism. She's robbed of that, becoming a fragile sixteen-year-old girl. And we bet Ian finds her easier to control now.