Artist’s description from DA:

Iron Will really didn’t have a whole lot of screen time in his only appearance in the show, which is a darn shame, because he was a pretty entertaining character. His little catchphrases and such cemented him as one of my most memorable “villains” of season 2. Though he wasn’t even quite a villain either. Unlike the Flim Flam Brothers, he wasn’t out to scam anyone, he legitimately thought he was doing everypony a service with his seminars, which to some extent I think he was. Fluttershy may have just taken the whole “assertiveness” act a bit too far. Also, Mr. Will up there is one of the very few clearly humanoid creatures in the series, being that minotaurs are sort of human-bull hybrids. So if humans don’t exist in the FiM universe, it’s a little odd that creatures like minotaurs exist in their place. Just a little food for thought I suppose. :T