so it seems they have several blessings that deal with seeing through illusions, but i dont recall anything that creates illusions off the top of my head. am i forgetting something? or are these just supposed to be GM made illusions?

When designing the blessings I was thinking of a number of Grey Magic spells that are described as illusions, I'd also say the blessing would see through things like glamours or the special ability of the Changeling and stuff like that.

It is ultimately up to the GM. If you wish to be strict about it the blessing could only work against those spells described as illusions. I would be tempted in my own games to allow it to be used in a more limited way against all manner of disguises, but I'd be much more vague about what the Verenan can glean from things that are not technically illusions.