After relocating Grim's banking headquarters into downtown New York City, he knew that he would need to find somewhere out of the way that would allow him to keep his... nastier habits of consuming human flesh under the table. Or more accurately, in the basement. In the suburbs of Jersey City is a pleasant, unassuming building, just enough space for a small family, while still being comfortable. It just so happens that there is a secret door hidden in the house leading deep underground. In that underground space is a padlocked and sound proofed door, hiding the victims of Grim's unholy tastes. But no one but Grim and a few sorry, sorry souls from Jersey will ever know it even exists...
After a year spent training under the great killer Jack the Ripper, Grim realized that there was more to hiding yourself from the law then just being sly - influence and funds. Starting small in the early 1900s, some lucky investments in weapons manufacturing as it moved into the Great War allowed Grim to amass a small fortune while keeping his tastes a secret. After he outgrew his old stomping grounds, Grim made his way to the Americas to continue his investing prowess, further amassing his wealth, building his banking empire: Satan's Investments National (SIN). He now spends his money on keeping up his lavish lifestyle by throwing parties and keeping people happy to distract them from his sinister hobbies.
Grim is bound by the origins of his existence to consume human flesh to sustain his form. It's only natural that he would prefer to make it easier for him to thrive, and not just survive. Grim intends to subjugate the human race beneath his boot to keep them powerless to stop his feeding frenzy. It's only a benefit that the humans crafted the perfect systems to keep themselves subjugated. He now uses his money and influence to keep the humans poor and he and his allies above them. He spends time lobbying for deeply capitalist movements, and will make anyone that gets in his way... disappear thanks to a terrible accident, ending up in a dark basement instead of the morgue...
Grim's most defining moment was his birth, or more accurately, his creation. Grim was sewn from the heart of an evil man ritually sacrificed in the moment of the commitment to a violent act against his fellow man. Consuming the man whole to create his own body, he was nursed by the satanic cultists into a more powerful form in hopes of using him as a weapon against the forces of good. Instead, he one by one consumed them all, until the cult was annihilated, and he had reached his first stage of adulthood. From there, he would journey out into the world, and learn that violence was not the only way to manipulate the humans...