History of Youngblood

Youngblood is one of the first Image Comics superhero team. Youngblood is a government superhero team. A major theme of the comic is superheroes (in this case, the Youngblood members) being treated as celebrities.
Original Team

Clockwise: Diehard (top left), Battlestone,
Shaft (not member), Chapel

The original team was sent to Saddam Hussein stand-in Hassan Kussein / Kussain (his surname is spelt both ways). It was led by Battlestone. However when Gamble talked back to Battlestone, Battlestone murdered him. Diehard captured Battlestone and the team went back to America to put Battlestone on trial. Battlestone was fired, but otherwise unpunished, by corrupt politicians. Battlestone called them monsters for wanting to activate another clone. The members of this version were:

• Battlestone- John Helix Stone was the leader. He had a no nonsense personaility. He also appeared to mentally unstable since he killed someone for talking back to him. He got away free via corrupt politicians.
• Diehard- He is supposedly a "genetic superman". In reality, he is a cyborg. He has super strength, flight and durability. He also has a Captain America-like shield.
• Gamble- He seemed to have not any superpowers. He was killed by Battlestone. According to the politicians, he was a clone that they can replace.
• Boggs- He seems to have not anything superpowers. According to the politicians, he is a clone that they can be replace.
• Chapel- He is a "cold-blooded killer for hire". He uses guns since he lacks any superhuman abilities.
• Riptide- She is the sole female member. She has water manipulation and generation.

Home and Away Team

Away team (clockwise: Riptide, Sentinel (middle), Psi-Fire, Cougar, Photon, Braham)
Home Team (close wise: Badrock, Chapel, Vogue, Shaft, Die Hard, Combat)

The original team was absorbed into the second version. This version was split into two teams: the Home Team and Away Team. This team did various tasks for the government such as killing Hassan, fighting the alien invader Dark Thornn and recapturing the villain team the Four. The government formed the Bloodpool team to train new members. Despite foreshadowing, clones of Gamble and Boggs weren't members. Things started to go wrong when Crypt killed several superheroes. The Home Team consisted of:

• Bedrock (later Badrock)- Thomas John McCall is a teenager. He was transformed into a rock monster via drinking a chemical. He has super strength and durability. However, he acts like a teenager. His name was altered to avoid a lawsuit from Hanna Barbera (creators of The Flintstones).
• Vogue- She was a Russian woman forced to flee to America due to the KGB killing her parents. She is trained in hand-to-hand combat. She has a cosmetic corporation.
• Shaft- Jeff Terrell is a government agent. He was assigned to lead the team. He uses a bow made out of anti-gravity technology (thus removing the need for a string).
• Photon- He is a renegade alien with fire powers (although the fire is green for some reason) and flight. 
• Diehard 
• Chapel

The Away Team included:

• Sentinel- Marcus Langston used a special suit of Iron Man-like armor. This suit gave him flight, super strength, invulnerability, blasters, force field creation. He had a generator in his chest that powers his suit.
• Combat- Kh'ambt is an alien from a honorable warrior culture (although this trait is missing in his first appearance). He has super strength, invulnerability and alien weapons.
• Psi-Fire- David Waller was an psychopathic and sadistic member. He has telekinesis.
• Cougar- Daniel Tsuchida is an immigrant with animal-like features and powers.
• Braham- He has super strength and invulnerability.
• Riptide

However, the team didn't stay with just these members. More members joined. These new members included:

• Knight Sabre- Mikey Graves can absorb aggression and anger then convert it into kinetic energy. He can manifest this energy in a variety of ways.
• Dutch- Jake Holland joined to stop his former friend Gigger (who went evil). He is at the peak of physical perfection and has technopathy and guns.
• Troll- Bartholomew J. Troll is a thousands of years-old troll. He intentionally acts as the team's comic relief (which increased his popularity). 
• Sentinel II- Brett Butler was hired as a replacement for Marcus (although he would return).
• Alan Keever- He is Youngblood's liaison with the US government.
• My sources mentioned Lucifer / Alexander Graves and Die-Hard II. However, I think these were mistakes since I couldn't find any evidence of their existence.

Third Team
Battlestone formed a third team. It mainly consisted of members of previous teams. Bloodpool was absorbed into Youngblood due to budget restraints. Riptide was killed. Although Knight Sabre seemed to have done it, Toby King revealed Sentinel killed Riptide. After Marcus was imprisoned, the team disbanded. Members were:

• Sentinel- Marcus Langston stole a magic book that could rewrite history. He rewrote the book to alter his future. When Riptide got the book, he attempted to steal and ended up murdering her for it. He framed his teammate Knight Sabre, but Toby King revealed the truth. Marcus was imprisoned in Supreme's Hell of Mirrors.
• Task- Ryan Orsini was genetically altered and experimented upon on a molecular level to make him a juggernaut in combat. This gave him super speed, strength, healing and durability. 
• Psilence- Monica Caine is a mute psychic.
• Alan Keever
• Battlestone
• Badrock
• Diehard
• Riptide
• Cougar
• Vogue
• Dutch
• Shaft
• I couldn't find any info on Lord Dredd 

2009 Youngblood

Clockwise: Badrock (top), Johnny Panic, Shaft, Cougar, Doc Rocket and Diehard

The US government reassembled Youngblood. This was little more than a PR stunt. However, the team went rogue upon discovering an actual threat: an insane ex-Allied Supermen of America member Spacehunter. After they did so, the US government formed another team to replaced the rogue members. Rob Liefield randomly interrupted the plot with a new Youngblood team and no explain what happened to the previous plot. The president was kidnapped by a future version of Badrock and someone called "Jeriko". No issues were produced after this. The first 2009 Younglood team consisted of:

• Task- Ryan Orsini was assigned to become the leader of Youngblood when Shaft was thought dead. However, the other heroes did not respect him.
• Doc Rocket II- She is the granddaughter of the Allied Supermen member of the same name. Like her grandfather, she had superhuman speed.
• Johnny Panic- John Paneczik is the world first "post-postmodern" superhero. He uses a chemical that gives him illusion creation.
• Badrock- He became injured mid-series.
• Diehard
• Cougar
• Shaft

The next team was:

• Sentinel III- The title of Sentinel was given to an unknown person. He wore the same armor Marcus did (since the armor was property of the US government). 
• Spyke- She was a said to be an unpredictable and temperamental member. She has claws coming out of her hands that she can use as weapons.
• Jamm- He was a flamboyant member. He has super reflexes and sonic powers (although he never uses the latter).
• Hatch- He is a former black ops member. He is described as being a combat specialist.
• Sundance- She is an immigrant that has fire powers.
• Task

Liefield's revamp team included:

• Sentinel IV- Kiesha Langston is the first Sentinel's sister. She designed the Sentinel armor. As such, she was given the armor to pilot.
• Big Brother- He is a man in a giant robot similar to ones used in mecha anime.
• Badrock
• Diehard
• Photon
• Vogue
• Shaft

References:
http://www.weirdspace.dk/RobLiefeld/Youngblood.htm
http://www.weirdspace.dk/RobLiefeld/MarcusLangston.htm
Youngblood issue 0 and 1
Atop the Fourth Wall episodes "Youngblood # 1", "Youngblood # 2", "Youngblood # 3", "Youngblood # 4" and "Youngblood # 5"
http://tvtropes.org/pmwiki/pmwiki.php/ComicBook/Youngblood?from=Main.Youngblood
http://www.weirdspace.dk/RobLiefeld/Photon.htm
http://www.comicvine.com/combat/4005-27429/
http://www.comicvine.com/troll/4005-5183/
http://www.comicvine.com/dutch/4005-5246/
http://www.comicvine.com/knight-sabre/4005-5185/
http://www.comicvine.com/psilence/4005-5186/
http://www.comicvine.com/task/4005-5184/
Youngblood (2009) volume 1 and 2