Not completely sure if I'd posted this idea before, but here goes:
An isometric Supernatural X-Com esque open world game. Set in ye olde late 1800s-early 1900s, basically the setting of Dracula. Assemble a team of supernatural investigators and monster hunters, with a variety of skills that you can either build up from scratch ( for the generic Hunter ) or choose from certain archetypes:
The Scholar: The Professor, the Academic, the guy who makes, keeps and uses notes to fight the terrors of the night. All monsters in the game have weaknesses, somewhat randomized every time a world is generated ( eg running water affects some vampires, some affected by iron, others by silver, etc. ) and a character after a successful mission, depending on their Scholarly Skill, creates automatic notes which give corresponding boosts provided you prepare the right equipment at the start of each mission. Other advantages include interpreting ancient tomes and grimoires, accessing local libraries for local lore, etc. Weaknesses are what you'd expect, if you don't prepare, scholar's just a generic mook with no real bonuses.
The Priest: Clergy sent by the ill-defined denomination of this pseudo-European world's vaguely Christian church, in terms of knowledge, gets bonuses like the Scholar above, but only for what the church specializes in, demons, witches, etc. Has special power of mana faith, useful against monsters vulnerable to that sort of thing ( again, may vary world to world ), rejuvenated by prayer and successful protection of the innocent, shaken by losses, both of battles and friends. A faithless priest is extra vulnerable to possession and mental/spiritual torment, so don't run out of faith in the middle of an exorcism.
The Psychic: Certain monsters ( ghosts, poltergeists, demons, other psychic anomalies ) are invisible to the naked eye, and difficult to fight without proper knowledge and weapons/tools. Psychics are born with the ability to interact/fight with immaterial beings, possess upgradeable Carrie-esque powers, and can also extract information from the minds of others. Call of Cthulhu-ish sanity as a mechanic is present for every character, and when one comes into contact with the terrifying and horrible, as will likely happen every mission, the psychic is the one that sees the most, and loses sanity the fastest. A psychic possessed by a demon or eldritch being will have more than enough power to nuke the rest of your team.
The Rogue: The Bruiser, a man/woman who had to be sharp to survive life in the slums, with an innate inclination towards violence and weapon skills. A lifetime of seeing human monstrosity has hardened them to supernatural horror, so they gain a bonus to sanity and courage. Downside, if one were to only specialize in Rogue skills, is that they can only fight on a human level. Any ordinary bloke would be smashed in a fight, a werewolf, or a ghost? Not so much. Archetype also may be more vulnerable to manipulation by creatures that play with negative human emotions
The Grifter: The people person, the natural born politician. Think Doctor Who level charisma and commanding presence in tense situations. When in towns, the cooperation of the locals may be just if not more important than understanding the monster's weaknesses or bringing the right tools. Information acquisition from witnesses will be made much less troublesome, and convincing them to aid and perhaps even fight alongside you is a possibility. Even the toughest vampire can only run from a large enough torch-wielding mob. If you can't get the people on your side, the Grifter has no real advantages, much like the Scholar above
Other archetypes would only add to the fun.
Skills related to each archetype can be cross-taken by members of your team, allowing for balance as opposed to specialization. World parameters can be adjusted, regarding monster intelligence vs. animalism, monster autonomy vs social cohesion, the amount of immaterial vs material opponents, etc. Sky's the limit, with randomly generated towns with varying populations, technologies, resources, and attitudes to the supernatural.
I swear I've written about this before. Still a fun idea.