Michael Morningstar

Michael Morningstar a.k.a. Darkstar is one of the many Plumber children that appear throughout the course of Ben 10: Alien Force. He appeared in the episode All That Glitters. His general appearance is that of a handsome human male with blond hair and light blue eyes. He is selfish and largely sees others as mere tools, or as batteries when it comes to girls.He seems to call Gwen lovely Gwen.

Alien Force
He is initially depicted as a well-mannered individual whom appears eager to help Ben and company. He comes from a rich family as he states that his family has multiple mansions, how his family acquired such wealth isn't explained but it is known his is the only family which has such wealth, which are armed with a menagerie of Plumber technology. The technology in question is monitoring equipment that uplinks to a variety of networks which funnels information to him. Part of the monitoring equipment features a communication network between the Plumber badges and presumably the homing signal mechanism that's built into each device.

As they travel with him he shows a very uncaring attitude to others around him. This is evident by his slamming of the door in Kevin's face as well as his remarks to Gwen while they are alone. He reveals his true intentions at the end when he drains Gwen completely as well as initiates a battle between the male members of the team. He is finally defeated by his victims as they take back the power he drained from them. When defeated his skin tone turns a dark grey and he looks almost dessicated.

He later reappears as Darkstar in Darkstar Rising, and try to get Ben, Gwen, and Kevin arrested by Magister Prior Ghilhil for impersonating Plumbers by making a deal with a Highbreed he defeated. When the Highbreed did his part of the deal he tried to absorb Ben, Gwen, Kevin and Ghilhil's energy but Gwen came in with the DNAliens in which he was unable to absorb all of them because of fatigue. He was defeated by Ben using a combination of his aliens, he was then arrested by Magister Ghilhil and thrown in the Null Void.

Darkstar is eventually released from the Null Void by Ben's team so he can help them stop the Highbreed invasion. During the battle, he tried to absorb the energy of several DNAliens, transforming his face back to normal, but Ben managed to talk him out of it. After the fight was over, Darkstar managed to escape them.

Darkstar appeared again in Trade-Off, when he fooled Kevin into finding him so that he could convince Kevin to join him to find the Dominus Librium to which they eventually retrieved and used the Librium to absorb their powers and return them to normal. Darkstar kept the Librium so he could still use his powers. When Gwen discovered the truth about Kevin, she confronted Darkstar in which he started to drain her power as well as Ben Tennyson's who came to the rescue along with Kevin, he was eventually defeated by Kevin by breaking the Librium and got his powers and ugly appearance again. Darkstar also got his powers and hideous appearance back too and he vowed that he would make them all pay someday. It is confirmed by Dwayne McDuffie that will learn more about Darkstar in Ultimate Alien.

Michael Morningstar
Morningstar's abilities allow him to absorb energy of another living being. He has however only exhibited this ability on female humanoids. Through the absorption of this energy he gains the ability to fly, superhuman strength and stamina, projection of bolts of energy and his skin tone becomes more healthier looking. When he absorbs a great amount of energy, as in the case of his draining of Gwen, he gains a membrane of gold over his skin. Presumably this membrane confers a certain level of resistance as well as super-strength as it does for Kevin. All these abilities are lost should he lose the energy he's absorbed. This can happen by means of him coming into contact with someone he's drained. Whether he needs to recharge or something of the sort is unknown but it is known that he likens his draining as a sort of feeding. His draining of people has a few after effects on his victims. The victims become attracted to him and may feel a slight level of infatuation after being drained a bit. Victims may exhibit a ring of bite marks from being drained. Finally after multiple drainings victims enter a zombie like state and their skin becomes grey.

Darkstar
In true "Doctor Doom" fashion after his first defeat at the hands of Ben, Gwen and Kevin, Michael Morningstar now wears a metal helmet/mask over his face. He has experienced some changes in his powers. While he seems to have lost his ability to fly, the powers he has are:
 * Superhuman Strength and Durability: Darkstar is strong enough to lift large pieces of rubble and rip open metal doors with his bare hands. He can easily withstand DNAlien blaster fire and being knocked back by a Highbreed. He is also durable enough to withstand several attacks from Ben's aliens, Gwen, Kevin, Magister Gilhil, and being stepped on by Humongousaur all at once, but it did knock him unconscious as a result.
 * Dark Energy Manipulation: Darkstar can now manipulate dark energy and display it as blasts of energy.
 * Absorption of Life Energy: He can now absorb energy through his dark energy rays which expands his list of targets exponentially.

Trivia

 * It has been confirmed that he is not an alien hybrid.
 * He was deemed by Kevin unworthy of being a plumber due to his self-benefiting attitude to his powers.
 * He has his own mansion.
 * He may be the only Plumber kid whose powers aren't derived from an Omnitrix alien from the original series (except for Pierce), and doesn't get his powers from an alien heritage.
 * Mike is considered to be Kevin's personal arch-enemy, ironically, both share similar powers i.e. to absorb energy.
 * Mike's surname "Morningstar" is another name for the fallen angel Lucifer and being the son of a Plumber, this is somewhat fitting.
 * Dwayne McDuffie said that he thinks Darkstar's the most dangerous enemy, Vilgax being the most relentless and the Highbreed being the most physically powerful.
 * In many ways, Mike is similar to the Marvel villain Doctor Doom; his mask, megalomaniacal personality and his hunger for power all attribute to this.
 * Dwayne McDuffie said that he is vampire (acting like vampire).