appearance
Well, you know I'm not going to make a Walter shrine without talking about his appearance somewhere, right? Walter's appearance is quite striking, obviously designed to impart a sense of strength and power even in something as non-threatening as a conversation.
About 90% of this information references Kojima Ayami's illustrations and is supplemented by screenshots/gameplay observations that show Walter from various angles.
physical
hair
Walter's hair is a fiery red and falls about his face in large, loose curls. Red hair is uncommon even in today's globalized world, appearing in only 1-2% of the human population. If we consider the setting of Lament, 11th century Europe (a reasonable assumption), it is safe to guess that red hair was a rarity. Considering the discrimination redheads still experience today, it's not surprising to learn that red hair and green eyes were thought to be the sign of a witch, a werewolf or a vampire during the Middle Ages.
Those whose hair is red, of a certain peculiar shade, are unmistakably vampires.
- Montague Summers, in his translation of the Malleus Maleficarum
Well. What else is there to say that doesn't wander into (more) speculation?
eyes
Unlike the stereotypical vampire of the Middle Ages, Walter has amber eyes, not green. Color symbolism is so broad that it's difficult to determine what was meant by a color choice (if anything, honestly), but it's interesting to note that yellow was a symbol of death in the Middle Ages, and orange can signify aggression, arrogance, and danger.
face
As expected, Walter's face is very pale, especially in Kojima Ayami's illustrations. I would point out that he's so pale that his lips are colorless, but Kojima almost never colors a male's lips, so there's no special significance in that.
Though Walter's features are beautiful, they are unmistakably masculine; his mouth is strong and wide, his nose is pronounced, his eyes are very striking, and his eyebrows are thick and wild. In contrast, Leon and especially Joachim have a less pronounced, more delicate appearance. Leon shares Walter's crazy eyebrows to some extent, but his lips and nose are smaller and more rounded. Joachim has delicately curved eyebrows, larger eyes, and an overall softer appearance.
Walter is also clearly older than Leon and Joachim; a Japanese guide gives his physical age as 42, compared to Leon's 22 and Joachim's complete mystery. *shakes fist* (Yes, this has always irked me. Joachim and Elisabetha are given ?? for age in the very same book that spills the beans about the other characters. Lame.) Anyway, Walter's face is more angular and shadowed than that of the younger men, giving him a more mature appearance. Interestingly enough, Rinaldo looks much older than Walter with his pronounced cheekbones and facial hair, but he is physically only six years older. To be fair, Rinaldo probably gained a few wrinkles after the loss of his family.
body
I'm going to behave myself here, honest!
Walter is almost completely covered by everything he's wearing - even his hair is partially hidden by his cape's high collar! We can still make a few basic assumptions about his body: he's tall and he's muscular.
In keeping with the Japanese anime/game stereotype, Walter is much taller than Sara, as we see in the cutscene where he returns her to Leon. It would be more reasonable to compare him to Leon instead, but it's impossible since Walter's standing on top of the stairs, way over Leon's head. Later, when Leon fights Walter, it's obvious that Walter is taller and just generally larger, though much of this bulk is contributed by his clothing and armor. check this -> Like Joachim, he also cheats by hovering above the floor instead of standing on it.
As for muscular, consider the massive armor he's wearing. I know vampires have superhuman strength, but there's no way a skinny wimp could wear such big armor; Walter's body has to pretty much fill the space inside the armor that's not taken up by his clothing. Even if he's wearing something heavy, that's still a lot of muscle in there. Walter also has very strong legs as seen in this illustration: insert link to full image and/or small image of thigh here.
His right thigh seems deceptively small until you realize that the piece of chainmail on top is covering part of his leg. When you consider it as a whole, that's one buff leg! Finally, look at the gold band on his upper arm; it's tight around the bicep and highlights the thickness of his arm.
clothing & accessories
Walter is buried under many layers of stuff. It must be a nightmare to get dressed and undressed!
armor & boots
Walter is wearing a massive suit of armor that completely covers his torso and much of his shoulders. The shoulders are upswept in an imitation of bat wings, allowing freer arm movement. The wing motif is repeated on the body of the armor with two red-veined wings folded over his chest in the image of an embrace. check this (it might be one large piece that wraps around under the inner cape) -> There are two pieces of chainmail that are attached to the inside of the chestplate; these fall down Walter's legs to protect the outside of his thighs. Drops of black crystal hang from the bottom of the chainmail as a very sparse fringe.
He wears high boots that cover his legs almost completely, leaving only the upper half of his thigh unprotected. The boots are metal from the knees down with a number of scales that jut out from the front and several sharp downward-pointed fins at the back of the leg. The knees are capped by a pair of metal demon heads, each with scales, horns, and wings; a classic representation of a demon. From the knees up, the boots appear to be made of black leather with black diamond-shaped studs. The top of each boot is bounded by metal decorated with more studs.
clothing
It's impossible to know exactly what Walter is wearing under all that armor, so we're limited to examining his arms, legs, and cloak.
note: I know next to nothing about clothing construction, fabrics, or anything else that would be useful when examining a character's costume. (My craft of choice is beading, not sewing.) If you have more information or ideas about Walter's clothing, please let me know!
Walter's cloak is black on the outside, and dark purple-red or deep orange on the inside. (Hooray for consistency!) It's a very full cloak, as seen in the fight with Leon; it fans out behind Walter as he turns, clearly cut from a circle rather than a simple rectangle of fabric. The collar is very high, reaching nearly to the top of Walter's head, and extremely wide, with its slender "wings" stretching out almost as far as the shoulder wings of his armor.
Walter's arms are completely covered by his loose sleeves and heavy gloves. The outward-facing surface of each sleeve is covered with an elaborate red pattern of leaf-like curls, echoing the curls of his hair. I can't tell if the pattern is supposed to be embroidered or if it is somehow embossed onto the fabric, since in Kojima's illustrations it's obviously just painted on over the finished sleeve. The fabric used for the sleeves is thick and heavy.
Walter's gloves are tight around the hand and somewhat loose about the wrist, probably to cover the ends of his sleeves. There are three rivets (maybe buttons, but that's not accurate to the time period - like Konami cares :p) in a line at the wrist. The gloves flare out in a triangular shape after the wrist, and the edges are heavily decorated with gold. The gloves look shiny in Kojima's illustrations and may be leather.
Walter is wearing some sort of coat under his armor; its long cape falls to the floor behind him, creating an attractive two-tiered effect when he turns quickly (to punch Leon in the face :p). The coat is solid black with a true red lining, unlike his purple-red/orange cloak lining, and is made of a lighter material. The coat is a different style from Joachim's as the cape does not wrap around to the front of Walter's body at all.
Finally, Walter is wearing simple black pants that are mostly covered by his armored boots.
accessories
Walter is heavily accessorized, a sure mark of wealth and possibly of rank. I'm surprised that Konami hasn't gone the Square-Enix route of selling overpriced jewelry replicas from its games. I'd buy an Ebony Stone for sure. ♥
Anyway, Walter's most important accessory is the Ebony Stone, which is kept close at all times. The stone itself is a black cabochon that is set as the focal piece of a heavy gold necklace. The rest of the necklace is made of textured gold beads that have some sort of black etching. (I want to say oxidation, but that's silver, not gold.) The necklace is obviously intended to match Walter's other jewelry; the tassel on his cloak clasp, the gold armband on his right arm, and his belt are all decorated with the same black etching.
All in all, Walter is very coordinated. His earrings are an exact match for the crystals attached to the chainmail portion of his armor, the elaborate pattern of his cloak clasp echoes the red patterns on his sleeves, and the heavy belt with its gold medallions and heavy chain matches his other pieces.
Naturally, Walter's accessories are made of gold instead of holy silver.