Ferrofluid Zac
you those who don't know "Ferrofluid" is iron ground up so much that it acts like a liquid. when you put a magnet to it is turns spikey and forms shapes much different from water, even when it is just sitting there. So what I am proposing is a skin with Zac made of the stuff and his abilities based around what happens when a magnet is put near it.
Video made by "The Slow Mo Guys". (don't sue me)