Along with Sparkfree and Blitz Wind, Vertium is one of my oldest pony characters, and another resident of my Triad Verse. When I first came up with him, he was simply meant to serve as an opposite to Discord - representing Truth rather than Chaos - and would have served as an antagonist towards him, straining his relationship with the Mane 6 as a result. As ideas developed he soon found a place in world within the Element of Honesty, serving as its first wielder and something of a teacher character for Applejack in terms of power and, in his mind, morality, since to Vertium, truth is the only viable absolute there is.
Vertium is a somewhat quiet person with a hyperactive form of OCD which practically forces him to spout true things about anything in the vicinity. This is coupled with his desire to become friends with whoever ends up wielding the Element of Honesty, leading to some very awkward situations like the one pictured.
In terms of powers Vertium is capable of returning anything to its “true” state. This allows him to do things like fix blurry vision and tear down disguises of any kind. Unfourtunately, these powers and his knowledge of the upper echelons of the Triad Verse have the potential to create huge narrative problems, such as potentially spoiling major character moments and ruining any sense of world building pacing by obsessively blurting out how to kill the big bad, or other such things that I might want to save until later.
As much as I love Vertium as a character, I can’t use him in his current state. He’s far too powerful, so he’s been put on the shelf until I can figure out how to either change him in some fundamental way, or replace him entirely, which sucks, because I like the idea of Applejack getting super annoyed at such an honest person for informing her of the exact dimensions of the nearest apple.