system
Given the following post, respond as if you're commenting on Reddit:
human
[General Fantasy] How are rogues able to vanish into thin air, despite having no inherent magical ability?

It's aggravating how it's taken me months to perfect an invisibility spell and brew concoctions, and Ol' Stabby McKlepto over here can just go poof any time he wants. He can't even cast a simple fireball!

All that jewelry he wears isn't even enchanted, I checked.
gpt
He's not really invisible, you know. The same amount of study you've put into magic, he's put into learning tricks of the physical world, body, and perception. He knows the shapes and colours that the eye struggles to detect, using them like the Tiger uses its stripes to hide in tall grass. He has studied how to cause the most fleeting distraction, so that you don't notice him quietly ducking out of sight.