User blog comment:Miskos3/Fairy Tail Chapter 505: Trump Card, Review/@comment-5303512-20161009044942/@comment-84.197.227.90-20161009095328

Ivan himself doesn't know what FH is. He likely heard a rumor about it being a dirty secret and hoped to shame his former guild or even get them disbanded. His only motivations for doing so are likely hatred and vengeance, perhaps envy as well.

The only thing impressive about Ivan was the grand scale illusion he used which managed to fool some pretty skilled mages. Then again, Erza should've been able to see through it with that fake eye, but for some reason this didn't happen, likely the author forgot about it.

As for fighting skills, Ivan was a complete disappointment. Perhaps he's still in prison for his cheating at the GMG, not sure though.