Despite it's influence the X-Force actually had a rather short series. Still, they featured a vast array of characters.
Ben (Magma Dragoon) - If anyone profits from war it's this guy, with a mind that's completely one-tracked Ben has confidence in his abilities but isn't in the least arrogant. Capable of taking on multiple foes and dispatching them with relate ease, Ben often enjoy jumping into riots and beating the snot out of everyone he sees. Or he will jump into civil conflicts and blast both factions to bits or when the time comes beat the living snot of any super villain he sees.
When it comes to politics Ben is about as conservative as Andon of the Sinister Six is liberal, very vocal he let's people know when he's very displeased and will often take his troubles out on various X-Force members except for Classi who seems to calm the beast inside of him. One last note is that Ben is a very capable leader and thinks on the go an ability his former comrades X and Zero lack.
Classi (Web Spider) - What can we say there's something about Classi. In the dark times of 21XX Classi shines like a beacon bringing back the better, more optimistic times of 20XX where she comes from. She even makes bad boys like Ben and Alon stay good and keeps Andrew from using Bliss; She has that affect on people. Happy, caring and understanding she is the only member of the X-Force that's friends with Mr. Dragoon. In combat she's the only X-Force member who refuses to kill even when it's the only solution to a daunting problem; However she hasn't got any beefs with bashing a few baddies around.
Being a fan of anything Heavy Metal from the late twentieth century Alon's idol is Ozzy Osbourne and hopes to use the Sky Lagoon II's time portal to meet him one day. (Although there are rumors that he is an immortal). Combat wise Alon's strength is a huge asset and has been known to lift 20-story buildings and hurling them a few kilometers and his ice generating abilities are second-to-none.
When he feels like it he can be a fierce combatant generating fierce winds that makes it look like a hurricane came in but usually Tobias just doesn't feel like fighting.
When Gate challenged the X-Force he claimed to be Nth and that his motivations were to reprogram and use the X-Force for his own ends. However, this was revealed to be a lie.
In the Sinister Six's final adventure it's revealed that Nth was actually a future version of Gary himself. Unfortunately, due to the timeline changing Nth's history no longer existed and it finally caught up with him, erasing the mysterious presence from existence.
During Ice VS Red, Red created an army of Neo Dragoon he labelled the "Army of Darkness". The Megaman Community fought them using trickery at first, disguising themselves as an army of Magma Dragoons, but when this charade collapsed the more powerful Neo Dragoon army almost prevailed. When Red was destroyed in Ice VS Red the army was destroyed and Neo's powers quickly faded leaving Neo with only the powers of Magma Dragoon.
Mr Dragoon (Myron) - For shits and giggles Ben and Myron's creator built Myron to be one half of a great warrior. Ben was the brawn, speed and raw power (but Ben himself is no fool) Myron was the strategic and tactical half however Myron is a pacifist and opted out of the Maverick Hunters. Taking a job at a famous accounting firm Myron settled in to become a white-collar worker staying away from the Reploid Wars.
To say Ben and Myron's relationship is strained is a complete understatement when you put them in the same room they bicker like children and the confrontations sometimes get physical. However like brothers they still stick like glue and give each other the odd favor or two. When it comes to women Myron's the sensitive guy who's loyal and devoted to the object of his affection. Currently he wants to ask his old college sweetheart Alia to marry him but he hasn't got the courage to ask her and worse yet he's in a race with Rob and Gate for her hand in marriage.
Myron is a very complex character, he's no enemy of the X-Force but he's no friend either.
First seen as a stranger Ben casually runs over while driving. Ben calls in Mr. D to lead the team while he attends a convention with all the famous Megaman Teams (notably mentioning that the Mechanical Maniacs are absent). Mr. D, however babies the team and imposes nonsensical rules. In "Year of the Fox" he's captured by Dr. Nuji Yakasan and his mind forms a part of Pyro da Fox ... or at least that seems to have been the idea. Pyro shows no trace of Mr. D's personality and we next see him at a move concession stand giving Gauntlet a hard time (Mr. D tried to get a prestigious job, but that was the best he could do).
Double didn't stay dead, however. When we meet him again (in "Time Lost") he's been captured by the Maverick Hunters and imprisoned on Neo-Rykers Island. Unfortunately for him he was killed when the X-Force's timeline collapsed. He would be seen one last time as a zombie under Red's command.
Double's attacks include the "Reaper Slash" and "Thunderstrike" attacks which are self explanatory.
General Alan Reno - A military general who captures Magma Dragoon in "Year of the Fox". He plans to make an army of Pyros, but doesn't ever show up after the YotF prologue.
Dr. Nuji Yakasan - Developed new DNA patterns to fashion an army of super soldiers for General Alan Reno. Used a time machine to capture both Ben and Mr. Dragoon for his super solider experiment (Pyro Da Fox).
Nicole (aka "Nic") - Daughter of Dr. Ming Yu, she was killed by Sigma long ago. She was in love with Ben while he was in his human form and he still has some feelings towards her.
Michael - A prisoner on Neo Riker's Island, he helped create Magma and Mr. Dragoon. He escaped prison along with Double in "Time Lost".
Dr. Ming Yu - Creator of Magma Dragoon and father to two children - Michael and Nicole. Dr. Yu and Nicole were both killed by Sigma under orders when he was a Maverick Hunter.
Dr. Robert Yu - Ming Yu's ancestor, Wily's last assistant before "the great robot war" (although we never meet her). Stole the plans for Zero in order to make an even more powerful Reploid (likely the first steps in making the Dragoon Clan).
Gate - Is a brilliant yet eccentric genius who's only loves are his laboratory and his schoolmate Alia, when he was outcast by his colleagues for his misunderstood findings on Reploid engineering. Isoc (Dr. Wily) took him in and made him into his "son". But what Gate doesn't really know is that he's being used as a front for Dr. Wily's schemes and that one day Gate will take the fall for the master's evils.
In one encounter Gate claims to be the mysterious Nth and knows a lot about Ben's past. The X-Force battle Gate and High Max with Ben shifting in to several forms (based off his various identities on other Megaman teams) before taking Gate down. Gate himself would travel to the past and attempt to create an ultimate life form by capturing the Mechanical Maniacs and combining that into one entity - Frankie (In Mechs Series 3's I am Invincible). Ben, as Blaze Heatnix, helped the team defeat High Max, Gate, and Frankie.