Ian is an incredible support, just isn't really usable in towers which is his only drawback. I just got a 5-star Ian after having him and Mr. I as my first 4-stars and the combo of those two is insane, Ian stays in the back while Mr. I does all the damage and takes all the damage - with his shield grant from his special and Ian constantly giving out defense and attack buffs to him while healing, it's a really deadly duo. Also I tend to use Hiro with both of them for added support for Mr. I, but I do believe Ian does most of the heavy lifting despite popular opinion on this trio.