Artist Svetlin Velinov has illustrated twenty-five Magic cards, including six in New Phyrexia.
The first step of the creation of a card's art is its art description. The art description tells the artist what the card will do, what its flavor is, and what the mood of the illustration should be. Here were the instructions Svetlin was given for Flameborn Viron, including a lot of location details:
Color: Red creature (Phyrexian)
Location: Phyrexian furnace layer
Action: Show a "furnace wasp," an enormous (30ft / 10m tall) monster that strolls the hellish molten metal landscape of the Phyrexian furnace layer. Its armored carapace looks like burnished metal, but some parts of its underside are more organic, like the sinewy meat of an insect or crustacean. It's so vast that it doesn't even notice the other little furnace-layer creatures scurrying around down near its feet (if you can work them in).
Focus: The Phyrexian "furnace wasp"
Mood: A slow but vast monster, like the brontosaurus of the Phyrexian furnace-realms
With that art description to work with, Svetlin submitted a sketch to the Magic creative team:
The first comment from the creative team was "Why is Svetlin so awesome?" But this wasn't quite what they were looking for, so they asked Svetlin to do another version from a lower angle to enhance the drama.
That was even better than the first sketch, so Svetlin was given approval to go ahead.
Here's the final card as you'll see it in New Phyrexia booster packs: