I have to say that I'm pretty comfortable with this deck being so popular because I find it quite shitty and enjoy every win I get from being paired against it. First of all, this deck lacks a sufficient amount of counter magic. It's really nice knowing that almost all of your spells will resolve because FoW is their only counter. Secondly, I feel that people overestimate Shardless Agent. With he exception of cascading into Ancestral Vision, he's basically a imaginary Trinisphere to all of your spells which would usually cost less (BS, TS, Hymn etc.). His 2/2-body is barely relevant which you should have noticed by now. These rare Ancestral Recalls you'll get from him aren't a justification to run him in my opinion.