Marrowgrimm is a Mercurian forensic examiner and the current president of Titan's emergency service workers union chapter, UESW Local 1964. A spry 102 years old, Marrowgrimm is a cantankerous old battle axe, having little patience for fool arguments and reckless behavior. As union president he is a ferocious advocate for his workers in contract negotiations with Titan administration, making sure sufficient emergency response crews are on standby at any moment to guarantee no single crew needs to stretch themselves too thin by handling too many calls alone. As a fellow emergency responder he is not very friendly, taking a matter-of-fact approach to matters of fact and never sparing a laugh for a bit of levity. Overall Marrowgrimm is the sort of person you're glad to have on your side, and the sort of person you'd dread having to deal with sitting across the table from you. Just remember the scowl isn't anything personal, he's just like that with everyone.
In his time working as a forensic examiner, Marrowgrimm has seen many things, having pieced together the events that led to many catastrophic losses of life, determining whether a given incident was accidental or intentional and establishing whether the outcome could have been prevented. Life in space is dependent on mechanical and social systems, and a breakdown in either can lead to terrible results; Marrowgrimm's job is to establish reasons for these breakdowns so investigators can determine if someone was at fault. He carries a collapsible lantern and a monogrammed bag of forensic tools when he joins an emergency team on a site, preferring to trust his own equipment on a job over tools provided by others- he gets very precious about his things, so be sure to keep your hands off! He doesn't need your grubby mitts compromising his investigations.
Marrowgrimm has a very strong reputation for surfacing forensic truths, and part of that comes from his innate Mercurian talents. Being the bearer of a rare Curse of Sol- or a gift that is strong enough to pull a Mercurian towards calamity- Marrowgrimm's Mercurian purview is "Entropy". He is able to perceive the innate chaotic energy within a thing or a group of things and he can tell how close or far those things are from an irreversible breaking point, either on their way towards it or how far beyond it they have come. He describes "seeing" entropy as a bright pulse, a throbbing flash of heat that builds its rhythm towards a steady monotone, towards an entropic breaking point. A broken entropic dispersal of this heat appears to him like a flash of fireworks in very slow motion; motes of that throbbing heat scatters away from its break point in streaking lines, away from a specific moment of collapse. As a forensic examiner Marrowgrimm can quite literally trace the trajectory of an entropic break back to its point of no return, he can pinpoint which chaotic elements disrupted a system and he can use that insight to find the information he needs to present his assessment of an incident site to his non-Mercurian peers.
In his Firewalker Form Marrowgrimm is able to accelerate or reverse entropic breakdown, which is a harrowing power to know someone possesses. If he wants to he can accelerate the wear and breakdown of physical materials, he can expedite or reverse the aging process within an organic body or, if he needs to, he can un-break an egg. He does not like to unbreak eggs, but sometimes, if he absolutely must, if he feels it is his only way to determine a cause for harm and calamity that eludes even his own vision, he can bring the dead back across the entropic threshold, to hold them here for long enough that they might tell their own tales, that they might name a name or speak a truth that would otherwise be lost with their own passing. Some eggs can remain unbroken when his Firewalking passes, but the spark of life, once that energy is released, it must continue on its course and trajectory. When Marrowgrimm has troubled the dead long enough, he will ease them back into their entropic release, and return them how he found them. If one knows he has this ability, one must never ask him to use it. You will not be able to unbreak the eggshell of his scorn.
In addition to his work as a forensic examiner, Marrowgrimm is occasionally contracted for private work of an unusual nature. It's known that ghosts can become a problem in space; it's rare, but every now and then a starship passing through a point of space that saw a traumatic event could become a new anchor for the ghosts of former starfarers from years, decades or even centuries past, and now that ship is haunted. Getting rid of a ghost hitchhiker can be a big problem- some are quiet, some just stare, others can be quite loud and others still could become violent, smashing or throwing objects on a ship. These ghosts have unresolved business and it's usually not possible to immediately discern what they want to resolve before they can pass on, so you'll need to contact a professional to see them off with their business un-settled. Marrowgrimm is one of the guys you call to take care of a ghost problem. Having mastered his Curse over an eventful century, Marrowgrimm is able to entropically decay the bonds that chain a ghost to this plane, dissolving the weight that keeps them in our world and forcing them to drift away into their final destination. It's a grave task depriving someone of their eternal closure in this way, but we can't always know what they want and these starship crews can't provide that closure themselves. It's bitter work but Marrowgrimm will do it. He's very expensive, though. These grim labors take a toll on everyone.
Being able to see the chaotic pulse within everything around him, to see how close to breaking anything is, it's a weighty curse. Mercurians generally look out for one another, it isn't a hard or fast rule but culturally a Mercurian would be hesitant to, say, narc on another Mercurian's scam, or hunt another Mercurian's bounty, or otherwise give up a fellow Mercurian to a power or authority outside of their own. Mercurians like to handle their business internally, and while they absolutely don't all like each other, when faced with an outside force they find solidarity with each other very quickly. Marrowgrimm stands out against this context in that he hates other Mercurians, he can't stand them. Bearing their Gifts of Sol, Mercurians are a very entropically-volatile people, testing fate and riding rockets towards their own explosive ends. Having been around for a full century, a fair few Mercurians have heard stories of Marrowgrimm, or they know that someone like them is out there who can un-break eggs, who can undo the calamity their own Gifts of Sol might cause. Enough Mercurians have asked Marrowgrimm for the favor of his Curse, to undo a mistake they wouldn't have made in the first place had they a mote more restraint, that he has developed a bitter resentment towards his Curse and his people. A younger Marrowgrimm would agree to undo a catastrophic but genuine mistake if it meant restoring another person's wholeness, but this has happened often enough that today's older Marrowgrimm will refuse to use his abilities to help anyone avoid accountability for their own recklessness- the outcome they want reversed is a severe lesson but it is one they must grow from. He can see their chaotic tendencies and he has heard enough pleas to put the entropic toothpaste back into the tube, he resents that you would force him to say no to a request for a kind of help only he can provide.
Marrowgrimm is a bitter old man who has seen a lot of breakdown and decay in his lifetime, but he is still a Mercurian himself. He won't sell out a confession like this from another Mercurian- he will give you hell and festoon you with guilt, but he won't ever turn you over to a Star Patroller or Titan Administration. He won't unbreak your eggshells, he will hope that cleaning your own spattered egg yolk will make you a better Mercurian in the future, that the experience of dealing with your own broken eggs will give you the gentle restraint needed to better handle your eggshells in the future. He's a mean bastard, but that's why his union elects him president. It's better to have him fighting for you than against you, you can be sure of that.