Heads up to all... This entire team is completely tech based so don't really expect any metahumans, wizards or anything of the sort. SO let's get started!
1. Lex Luthor ( Muscle, Brains, and Leader)
Honestly when I wrote that I wasn't referring to regular run of the mill Lex. Sure he's got his advanced intellect and all that, but I meant him in his warsuit. Some abilities of his warsuit include Superman level strength, enhanced speed and durability, energy blasts, Kyrptonite Blasts( red, blue, and green), and a close range blade, missiles, electrical blasts, and energy based force fields. I honestly think he could pull off the leader gig because he's smart, cunning, and has lead both the Injustice League and the Legion of Doom, and is currently a member of the Justice League.
2. Boba Fett (Artillery, Bounty Hunter)
So as you know most versions of Task Force X have at least one mercenary on the team (Deadshot and Deathstroke) but this bounty hunter has so much gear that he's literally referred to as "A Walking Weapon" Some of his arsenal include a Fibercord whip with a grapple hook, Czerka ZX Miniature Flame Projector, Mitronium Z-6 Jet Pack, Sonic Beam Weapon, Survival Knife, Knee-Pad Rocket Dart Launchers, Blastech EE-3 Blaster Rifle,Turbo-Projected Magnetic Grappling Hook with 20-meter Lanyard and many MANY more computer and armor based things on him. So basically this guy has so much firepower and protection that he should be the first to charge into a battle.
3.Syndrome (Comic Relief,Brains, Sociopath)
Oh Man! This guy has that perfectly sarcastic yet sociopath like attitude that this grim team needs! Abilities of Syndrome include Control over Zero Point Energy, Super Intellect, and control over his Omnidroid army. He mainly fits the comic relief because he laughed straight at a Super-Strong hero who was captured, which probably isn't a good idea because Mr. Incredible breaking out = Your DOOM. He's so hyper-intelligent that he invented a robot that adapts to individual superheroes fighting styles to basically terminate them and have his Omnidroids learn to be able to expect future attacks from other Supers, and thus make him the only remaining "hero" alive. Also, he spent a ton of money paying for both food and transport for Mr. Incredible just to ruin both his family life and to literally end his life.
4. Nebula ( Assassin, "Girl")
And finally, I chose an actual space assassin trained by Thanos himself! And technically she's tech based due to the fact that she's a cyborg with robotic headgear , two prosthetic arms, and a cyber eyepiece. I said that she's a "girl" character because she's a girl sure, but she's not exactly girly, like Princess Leia ( No offense fellow Scruffy Nerf Herders ). I said assassin because some of both her training and weapons which her training is straight from her father, Thanos, and her weapons are dual shock batons. Some cybernetic enhancements she has includes Regenerative Healing, Contact Whiplash, Tempersteel Claws, and Concussive Blades. And some natural boosts of her species, the Luphomoids, include Superhuman Strength, Superhuman Durability, and Superhuman Agility.