Overview
Gambit (Remy Etienne LeBeau) is a fictional character appearing in American comic books published by Marvel Comics, commonly in association with the X-Men. The character was created by writer Chris Claremont and artist Jim Lee.
Gambit belongs to a subspecies of humans called mutants, who are born with superhuman abilities. (Okay, so it looks like we are making a Variant Human. Could also reskin another race with similar attributes; will probably use custom species rules in Tasha's Cauldron of Everything.) Gambit has the ability to mentally create, control, and manipulate pure kinetic energy to his desire. (In D&D, there is no such thing as "kinetic energy," the closest analogs are force (as a damage type) and telekinesis (like mage hand, levitate, etc.) He is also incredibly knowledgeable and skilled in card throwing, hand-to-hand combat, (unarmed strike) and the use of a bō staff. (quarterstaff) Gambit is known to charge playing cards and other objects with kinetic energy, using them as explosive projectiles. (casting Magic Missile, or Eldritch Blast, with a deck of cards as the focus? The explosion is tricky though; perhaps a reskinned Fireball that does force damage instead of fire?)
He was part of a thieves' guild before becoming a member of the X-Men. (sounds like the Charlatan or Criminal background) Given his history, few X-Men trusted Gambit when he joined the group. There was consistently a source of stress between him and his on-again, off-again love interest and eventual wife Rogue. This was exacerbated when Gambit's connections to villain Mister Sinister were revealed, although some of his team members accept that Gambit honestly seeks redemption. (Secret identity and love triangle makes the Charlatan background more appealing.) Often portrayed as a "ladies' man", Gambit has shown a more vulnerable side of himself over the years, especially when it comes to Rogue. Gambit is a Cajun from New Orleans; he is fiercely proud of his heritage and speaks both Cajun English and Louisiana French. (Knows at least two languages.)
Fictional character biography
Early life
Remy Etienne LeBeau was born in New Orleans, Louisiana. He was kidnapped from the hospital where he was born, then raised by the LeBeau Clan Thieves' Guild, and given to the Antiquary as a tribute. (Could also go with Urchin background? Nah. Worse comes to worse, I could just create a custom background that mashes up Charlatan, Criminal, and Urchin.)
They referred to the child as "Le Diable Blanc" ("the White Devil") and believed he was prophesied to unite the warring Thieves' and Assassins' Guilds. Soon after, Remy was placed in the care of Fagan's Mob, a gang of street thieves who raised the child and taught him the ways of thievery. After living as an orphan on the streets, a 10-year-old Remy attempted to pick the pocket of Jean-Luc LeBeau, then patriarch of the Thieves' Guild. Jean-Luc took the boy off the streets and adopted him into his own family. (Could be a Charlatan-Criminal mashup, per the rules in the PHB. Call it "Street Gang" or something?)
Remy's bio-kinetic charging abilities manifested early in his teens, although he kept his powers secret from his family and friends, practicing his powers away from prying eyes. (Here we go, the stereotypical Sorcerer origin story.) When he was 15, he accompanied his cousin Etienne Marceaux on his "Tithing", the ritual initiation test of the Thieves' Guild. However, it went awry as they were assigned to steal from the powerful immortal mutant Candra, who quickly captured them. Remy used his powers to escape their holding pen...Remy was ultimately rescued by the Guild. (More background info)
Later during his teen years, Remy was first hired by Mister Sinister.... Remy and the Thieves' Guild accepted the mission and sent out Remy to retrieve said diaries. Standing in the cold, scouting the Weapon X facility, Remy could not bear the cold and swore he would steal a long, stylish jacket in New Orleans after the mission, which he did. (Interesting way to connect some starting equipment to the backstory. I'll have to remember to give him a cloak or something.)
Powers and abilities
Gambit is a mutant with the ability to convert the potential energy stored in an inanimate object into pure light kinetic energy, thus "charging" that item with highly explosive results. (This is going to be the hard part: I have to choose an analog for "kinetic energy" and stick to it. I think Force damage is the way to go for attack-based "kinetics," and I think the rest can be handled with telekinetic effects.) He prefers to charge smaller objects, such as his ever-present playing cards, as the time required to charge them is greatly reduced and they are much easier for him to throw. (arcane focus?) The only real limitation to this ability is the time required to charge the object: the larger it is the more time it takes to charge. (will need a recharge mechanic. Recharge 1-2 might work for something more powerful than a cantrip. Maybe "Recharge (4-spell level)" for spell-like abilities that aren't cantrips? or maybe just use Ki points or something?) Most charging takes place through direct skin contact. (most of these abilities have a range of touch) The power of his explosions is dependent on the mass of the object he is charging: for example, a charged playing card explodes with the force of a grenade. (OH IS THAT ALL?! JUST a grenade?!!?) Gambit can also use his mutant abilities to accelerate an object's kinetic energy instead of converting its potential energy; for example, he can charge his Bo staff with enough kinetic energy and power to level a house. (I like the idea of a character who can charge his weapons up to deal bonus Force damage. Sort of like a paladin's smite, or a monk's Ki Empowered Strike.)
Gambit's ability to tap into kinetic energy also grants him incredible superhuman physical attributes (strength, speed, reflexes and reactions, agility, flexibility, dexterity, coordination, balance, and endurance), (Sounds like his custom species will grant him bonuses to Strength and Dexterity. Also describes a Monk's Evasion and Purity of Body) as his body constantly generates bio-kinetic energy and so is perfectly constructed for constant motion. (His custom species might also give him a cantrip or small group of spells...reskinned Tiefling or Drow?) This gives him an added edge that he has used to his advantage by developing a unique acrobatic fighting style. (Fighter? Rogue? Monk?)
The charged potential energy always in his body grants him the ability to build up charges of static electricity, and shields his mind from detection and intrusion by even the strongest and most powerful telepaths such as Emma Frost, Jean Grey, and even Charles Xavier. The shield has the added effect of destabilizing touch-based abilities. (Monks have the Stillness of Mind ability, but I don't think that's the same thing.)
Gambit also possesses an unusually strong and irresistible hypnotic charm that allows him to exert a subtle influence over sentient beings, leading them to believe what he says and agree with his suggestions. (A charm effect?) This charm is so strong and powerful that if given a chance, Gambit could even charm the Shadow King himself. (Yeah yeah, I get it, he can blow up a house by tapping it with a stick, and he can explode a tank by hitting it with a pebble...let's dial it down a bit. So he's really good at Charm Person, maybe his targets have Disadvantage on their saves?) The hypnotic charm does not work on those who know about it. (But but surely the Shadow King has at least heard a rumor about...you know what? let's not go there. Turn down the "Comic Book Nerd" dial a bit, CleverNick.)
During combat, Gambit customarily wears a suit of highly articulated light body armor and uses an extendable metal staff. (light armor, quarterstaff). He is extensively trained in martial arts, particularly Savate and the staff style art Bōjutsu. (Classic Monk build, except for the bit about armor.) He is an excellent hand-to-hand combatant, applying street-fighting techniques and acrobatics. (Yep, Monk.) Gambit is a skilled card-thrower, so he throws his charged playing cards at opponents with great accuracy. (Throw Anything feat?) He also excels in all aspects of thievery, ("all aspects of thievery" in D&D 5E can be summed up as "proficient in Sleight of Hand, Stealth, and Thieves' Tools." And all three are already in the Criminal background.) as he was adopted by the patriarch of a Thieves Guild. (Sounds like he gets his thievery skills from his Background. Criminal Background confirmed.)
Gambit was temporarily given the full strength and potential of his mutant abilities to battle his counterpart, New Son. (Okay, let's see what a 20th level Gambit looks like) At his full strength and power, (20th level) Gambit can control all aspects of kinetic energy down even to the molecular level, allowing him to manipulate the potency of his bio-kinetic energy to burn, cause molecular discomfort, incinerate, create timed detonations (and manipulate the potency of the energy release), fire energy blasts, defy gravity, heal wounds, charge objects within his line of sight without contact, manipulate the flow of time & space and effectively exist as an energy being. (So he becomes the God of Energy. Sounds like a max-level Sorcerer who specialized in energy magic.) Under such conditions, he holds sufficient power to cause another being to be unable to move—or unable to stop if in motion. He has been able to cause or simulate various energies by manipulating the kinetic energy present, such as infrared and microwaves, by increasing molecular agitation, or cold by reducing it. He was also able to use his powers to travel through space-time, cross dimensions, and remake realities outside of space-time by transforming himself into living energy which joined with the kinetic flow. Finally, Gambit was able to heal himself by stimulating his cellular activity. These enhanced powers were burnt out after fighting New Son, and Gambit has since returned to his original, somewhat lower power levels. (Sounds like an awesome adventure, where everyone gets to temporarily play their characters at god-level...but not really suitable for this build. It was fun to read, and it's a nice glimpse at the direction this character build might eventually take, but it's not really relevant at the moment. Disregarding this paragraph.)
However, after Sage jump-started his powers again, he was able to heal his blinded eyes—thus implying he is again able to heal himself —and is also able again to charge living things with energy. (Spending Hit Dice to remove blindness on a short rest? Access to healing magic? The paladin's Lay on Hands ability?) He was also given another boost when he was killed in an altercation with a drug lord and Faiza Hussain managed to restore him before it set in, enabling him to charge a bullet with twice as much explosive force than usual. He has later proven able to delay his explosions again, although this is difficult for him to accomplish. (These abilities are great, but they sound more like quest rewards, not part of the character's actual build. I'll keep them in mind, but put them lower on the list of priorities.)
After Apocalypse used the Celestial Technology to transform Gambit into the Horseman Death, Gambit demonstrates the ability to convert inert materials into toxic substances (such as transforming breathable air into poisonous gases) and has the potential to ingest diseases and plagues. It is apparent that the Celestial Technology never left his system, as seen during a telepathic attack against him that temporarily brought out the Death persona, which eventually killed the attacker. He also showcased new abilities he had not used before in this form – such as his Death Charge, which fueled his projectiles with dark energies that have the effect of either disintegrating or entrapping beings within his cards. His new transformation also affords him the ability to control the trajectory in which the thrown cards fly in, giving him more control over their vector path while in motion. He could also convert people to his mindset like he did with Northstar, Dazzler and several demons while in limbo. Gambit's body did subsequently return to normal. (Emphasis mine. This suggests that the Horseman Death arc was only temporary, possibly an adventure arc or one-shot, and therefore not a permanent part of the character's build. I'm gonna keep this part on the back-burner as well, and use it as filler if I need more abilities later.)