Ĭonversely, Sol hates working any harder than he has to, rarely putting much effort into anything that isn't related to his goals, and is often irritated by having to deal with opponents. Sol is seen by most people as crude and self-centered, even those who might call him a friend. He is also quite stubborn, never allowing the opinions of others to dissuade him once he has made up his mind. A lone wolf with a belligerent streak, Sol is actually an extremely intelligent individual who doesn't tolerate nonsense and gets "grumpy" whenever he cannot explain something with logic. Consequently, he is not very good at expressing himself, and tends to compensate by bullying people into line or simply steamrolling them. Sullen and unrefined, Sol only speaks to others when absolutely necessary. In the past, as "Frederick", he seemed to be a simple-yet-aloof scientist, who was content with having only two friends, not bothering to compromise his own integrity to appeal to others around him however, upon becoming a "monster", his prior unruly traits became much more pronounced. In later games, he is seen sporting long-sleeved, red leather jackets as well. Sol also wears a pair of black fingerless gloves, red shoes, and a multitude of belts, including a lone one on his left bicep. His belt buckle has the word "FREE" scratched on it and a drape of red cloth hanging down beneath. He wears a tight, black undershirt with the top half covered by a red sleeveless jacket, along with white jeans. As Frederick, he is depicted with either brown or blue eyes he sports a much shorter hair, a muscular physique and a white labcoat. He has muscular physique, whether he is infused with Flame of Corruption or not. The headband conceals the red brand on his forehead that would expose him as a Gear.
Wearing a red headband bearing the words "Rock You", Sol keeps his spiky, waist-length hair tied at all times. Sol has olive skin, brown hair and eyes, which are sometimes depicted as reddish-brown or golden with slit pupils-the latter of which is to distinguish his true nature as a Gear.