Info;

BASIC INFORMATION
Name: Cassius
Aliases/titles: Agent Cassius, The Traveler, Chowhound (by Ilsa)
Age: Appears late 20's to early 30's, but he has implied that he's older than he looks. Headcanon says about 50.
Canon Point: Flexible, but after Home Sweet Moon preferred.
Race: Moondweller (classified as "Other" in-game)
Element/specialty: Dark, fire and water, with melee and spear proficiency.
FIRST IMPRESSIONS
Appearance: Pale, abnormally so. His skin has a grayish tinge to it, which is a trait other moondwellers both from the moon and born in the Sky Realm share, either due to genetics or the conditions on the moon, even both in some cases. The most color he has are the color of his eyes, and the red liner underneath.
Fashion: Typical moondweller clothing seem to be robes and armor with a futuristic aesthetic, leaning towards freedom of movement rather than protection. He will always, always bare his chest no matter what though-- it seems to be a common fashion choice among moondwellers.
Height: 183cm, or approx 6'0.05".
Build: Tall and lean, but with decent musculature that's most obvious with his overly defined chest. He definitely made gains by fighting and working, and not being a regular at the gym. Some of his build may be influenced by being a moondweller, as they're all well-built either by genetics or augments, and everyone has very prominent chests.
Hair: A very pale grey-blond, very long and straight. It seems to be the exact same hue as his skin. Sometimes he puts it up in a tail, but Cassius prefers to let it fly free.
Eyes: A blue-green (electric blue?) that's unnatural for other races but shared by all moondwellers. There are rings in his eyes that look like camera lenses (maybe they actually are lenses?).
Voice: His voice actor is Masaya Matsukaze. He's husky and breathy, and rarely raises his voice.
Language: The skydweller common language, and moondweller speech. Moondwellers communicate via electronic sounds (which are transcribed as nonsensical anagrams in the EN script, and in katakana-based cyphers in the JP script).
Scent: Sometimes sugary, depending on what he's been eating recently.
Hand dominance: Ambidextrous. But he clearly prefers using his right hand for battle.
Literacy: He can read and write, but don't expect anything legible out of a man who grew up around computer systems.
Triggers: Cassius does not register emotions, thoughts, physical pain or memories the same way we do, and despite going through terrible things for a year, he's not at all bothered by any of that. He might not have triggers at all, considering his actions at the end of Home Sweet Moon/Stay Moon, though he may trigger other people instead by joking about the terrible things that have happened to him.
Other: Parts of his body have been augmented/replaced by cybernetics, though it's not immediately obvious. His digestive system and parts of his brain are confirmed to have been enhanced or replaced via moondweller technology (making him able to digest weird shit like glass, and store memories like someone stores and saves files into a computer). As such, Cassius will be affected if an EMP or anything similar is set off near him, with the exception of signal jammers.

abilities
Moon cybernetics: Native moondwellers get enhanced at some point(s) in their lives, cybernetically, chemically, possibly others that the game hasn't shown yet. Mandatory augments include an ability to survive the conditions in space (extreme temperatures, lack of air, etc.-- enough to survive entry into a planet's atmosphere), even more strength and durability than what they naturally have, digestive systems that can extract nutrients from almost anything (rocks and glass are part of a balanced diet), and a brain that operates like a computer despite still being organic, such as store memories like someone saves files into a computer drive. They're all augmented to the point that they can rebuild bodies and physically transfer brains over, or transfer the data from said brain to the new body.
Moondwellers can also keep undergoing procedures if they want, such as upgrading other body parts, installing translators, or completely halting their bodies' aging. For the most part, Cassius has the most common augments and was ranked only middling in strength, but he is already considered quite strong by baseline people. His most notable enhancement is a mechanical spine, which is was recently installed by Isaac, so some of its functions might not be typical for moondwellers. It does affords him a healing factor, the ability to dispel unnatural or magic-induced illnesses from himself and his teammates, and also dispel magic-based strength boosts that his enemies give themselves.
However, he can still be hurt because moondwellers haven't invented complete invulnerability (yet). EMPs and proximity to chaos matter will cause him to hang like a computer with too many programs running at once-- he can make a full recovery via forced reboot, but has to be out of commission from anywhere between hours and days to do so. If one of his cybernetic organs is heavily damaged, he can die if it's not repaired quickly. If an organ, whether organic or cybernetic, is removed instead, he's just dead.
Elemental magic: There are six elements available in canon, and Cassius can manipulate three-- darkness, fire and water. Cassius is not a mage, but these elemental energies determine what he's weak to and what he's strong against at any given time. If he's working with dark, he's both weak to and strong against light magic-- holy magic, JRPG-style white magic, and the "light side of the force" all count as light (but light-aspected healing magic is okay, he's not some zombie). If he's working with fire, he's weak to water magic and strong against wind magic. With water, he's strong to fire but weak to earth. His elemental affinities don't factor into his daily life, they only passively imbue his body and whatever weapon he gets his hands on. However, dark is his default and he's more comfortable/powerful with it, thus he'll be attuned to dark more often. He can only use one element at a time, and he can't switch elements in battle.
kinks
Orientation: Pansexual.
Preferences: Something important to note is that Cassius is a virgin. He's aware of sex and understands what it entails, but never delved deeper, so he really doesn't know what his preferences are... but he will enjoy oral (giving and receiving) very much because he likes using his mouth.
Dislikes: ???? He'll learn as he goes, honestly.
Top/bottom: Will gravitate towards topping, but has no problem being the bottom.
D/s orientation: Switch, most likely. But he has no experience in this, and will ask many questions about why this kind of thing happens. However, painplay done to him may take a while for him to warm up to, if at all, as he has an extremely high threshold for pain.
Romance: Actually getting him to realize that he's caught a case of the feelings may be the slowest of slowburns, but I can see him speedrunning into a relationship once he's finally realized said feelings.
FWB: The reasoning for why people have FWB needs to be explained to him first, but he would be open to it.
OOC ship/dynamic preferences: Crosscanon ships are best ships, but I love Eustace, Ilsa and Vaseraga as well. I prefer Cassius with serious characters, or people with a temper-- or both.
KINKS
Yes kinks are particular IC favorites. Maybe means I'm open to it, but would require discussion first. IC Limits are things the character would dislike, but I would enjoy playing out despite their distaste (and in some cases because of it). OOC Limits are hard limits that I will refuse to play.
You can hover over kinks marked with an asterisk to read a note.