I mean yeah, I mess around with skin color and eye color and I've even tried hair color a time or two, running around on worlds that have it, but she's got a real translucent thing going on. Turn around and she's practically disappeared, only she hasn't, just the light hitting her skin sorta melts her into the background a bit. Mom says she got more than her share of teleportation, which is fair, because I've got a touch more temportation. And we do well enough, grabbing each other's hands before we go.
Go where? Everywhere, really; by custom twins stick together. Usually it's me doing the going and her the sticking, though; she keeps track of details. Little stuff, mostly, like where we're supposed to be and where I'm actually at and how not to land in the middle of a tree teleporting so you get there on time unless you want to. Which mostly you don't, because most of the worlds we've been on don't like it when you're trying to be in the same space as a tree is, and then there are explosions and hospitals and people asking you how many fins they're holding up. Or flippers. Or fingers. One of those F-type body parts.
So I guess the first thing to say about Wil is, she's practical. Well, no, the first thing I said was, she's unusually pale, and good at teleportation. The second thing is she's practical, then. Only it ought to be first, because when you've got a sister who keeps you from exploding trees, the rest of it is just icing on the cake, right?