Darkstar

Michael Morningstar, also known as Darkstar, is one of the Plumber kids that appear throughout the course of Ben 10: Alien Force. He appeared in the episode All That Glitters and since became one of the most notable regular villains in the series. He has the ability to drain life force from living beings, he gained a grudge against Ben and his team after they accidentally caused him to turn into an awful zombie-like being who has to wear a helmet to hide his face. His plans usually involve gaining back his original face and feeding himself, though he seems to still be interested in feeding from Gwen's vast stores of Anodite energy.

History
Michael is initially depicted as a well-mannered individual who 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 up links 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. While Ben and Gwen quickly trusted him, Kevin knew since the beginning about Morningstar's true motivation (partially because of his jealousy, as Michael and Gwen tended to flirt with each other). After a fight with zombified schoolgirls from unknown origin, Kevin guessed that Michael was the one responsible for these zombifications. His guess later proved to be right when Morningstar drained Gwen's energy, becoming nearly unstoppable and easily defeating both Ben and Kevin. However, Gwen proved to have enough will to resist his control, and drained her energy back from him, as well as part of his own, leaving him weakened. His other zombie victims then turned against him, and took back what remained of his energy, leaving him almost desiccated and powerless.

He later reappears as Darkstar in Darkstar Rising, his powers having gradually returned much stronger and more powerful than before. In order to get revenge, he tries to get Ben, Gwen, and Kevin arrested by Magister Prior Gilhil for impersonating Plumbers and by making a deal with a Highbreed Lord he defeated. When the Highbreed did his part of the deal, Darkstar tried to absorb Ben, Gwen, Kevin, the Highbreed and Gilhil's life force energy but he was unable to absorb Gwen's because she escaped. He later captured Ben, Kevin, the Highbreed, and Gilhil and was about to absorb all of their life force energy when 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. Afterwards, he was arrested by Magister Gilhil and thrown in the Null Void.

In the two-part second season finale War of the Worlds, Darkstar is eventually released from the Null Void by Cooper Daniels so he can help them stop the Highbreed invasion. During the battle, he tried to absorb the life force energy of several DNAliens, transforming his face back to its original youthful appearance, but Ben managed to talk him out of it because Michael realized that he was killing real people under alien control. After the fight was over, Darkstar managed to evade them.

Darkstar appeared again in the third season in the episode Trade-Off, where he tricks Kevin into finding him so that he could convince Kevin to join him to find the Dominus Librium (a device that was decidedly alien origin and could restore the two of them to original human forms) to which they eventually retrieved and used to absorb their powers and return them to normal. Then he sucker punched Kevin in the face. Darkstar kept the Librium so he could still use his powers. When Gwen discovered the truth about Kevin, she confronted Darkstar and he started to drain her power as well as Swampfire's. Darkstar's full power was eventually perished by Kevin when he broke the Librium and got his regular powers and ugly appearance again. Darkstar also got his previous powers (and zombified face) back too and he swore that he would make them all pay someday before running away. Darkstar appears in the two-part first season finale Absolute Power, it is revealed that Darkstar is now in a weakened state and is forced to feed off the energy of stray animals just to survive and tries not to cause too much attention to himself. He was later found and recruited by Gwen to stop Ultimate Kevin. As payment, she changes his face back to normal using a powerful transformation spell and promises him mana, enough to keep him fully restored for a year. Michael then agrees to help her to stop Kevin, much to Ben's chagrin. Michael reveals that he kept a fragment of the Dominus Librium when it had exploded in Trade-Off, though it's ineffective. However, a strong energy surge would make it usable again. The group goes to Los Soledad and meet Cooper Daniels who also agrees to the plot. Both Michael and Cooper create a device while Ben and Gwen stall Kevin.

When Kevin becomes normal, Michael takes advantage of this moment and absorbs the vast powers and abilities of the Dominus Librium, becoming power-hungry Morningstar again, shredding off his clothes and becoming pure energy. However, Ben anticipated this plot and presses a button which causes Morningstar to become normal again. Ben reveals that he told Cooper to create a mechanism to revert the process of the absorption. Afterwards, Kevin punches Darkstar in retaliation prior from Trade-Off.

Darkstar reappeared in Couples Retreat here having reverted back to his ugly form. He broke into Kevin's garage to steal one of Gwen's spellbooks. He used a spell in it to summon the Door to Anywhere, but was badly injured while fighting Ben, Gwen, and Kevin in the process. Escaping his pursuers, Darkstar collapses at the foot of the open door, and Charmcaster appears, taking him to her castle in Ledgerdomain. Once in Ledgerdomain, Darkstar reverted back to his handsome form, now having access to an unlimited supply of Mana.

Charmcaster and Darkstar are engaged in romantic relationship, but Darkstar, of course, was only using Charmcaster for her power and the power of Ledgerdomain. After telling him her real name, Hope, Charmcaster planted a rune on Darkstar's hand that acts like the key to Ledgerdomain, so he can come and go as he pleases. However, Darkstar soon finds that the power of Ledgerdomain leaves him when he leaves the realm, so he returns there, but is pursued by Ben, Gwen, and Kevin. At Charmcaster's castle, Darkstar fights Ben and Kevin, ranting about how he'll take over Earth and Ledgerdomain, and keep the "lovely Gwen" as a trophy. Charmcaster confronts him about this, but Darkstar denies having meant it seriously and offers Charmcaster to join him in being evil. However, Charmcaster asks him if he remembers her real name. Darkstar, unable to remember, replies "Heather." Charmcaster becomes enraged, destroying her castle in a burst of magic power and also kicking out Ben's Team and also expelling Darkstar from Ledgerdomain, stripped of his powers and returned to his ugly appearance. Charmcaster closes the Door to Anywhere in Darkstar's face, despite his pleas for her to take him back. Ben, Gwen and Kevin then approach Darkstar, ready to beat him up and apprehend him once more.

Power and Abilities
Michael Morningstar has the power to absorb any type of energy (life force, mana, electricity, etc.), but his powers are a vicious cycle: the more life force energy he drains from others, the stronger and more powerful he becomes. But the more power he gains, the greater his hunger becomes. Michael is currently so accustomed to mana that he has trouble absorbing low-quality energy.

Even when he is Darkstar, His strength is great 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 Humungousaur all at once (which made a crater), but it did knock him unconscious as a result of the attack.

Darkstar is Michael's negative form. He is like this when his energy levels are below average. His face turned into a gray, zombified face. Michael Morningstar must now wear a metal helmet/mask over his face. His powers change while he is like this. They include the following:
 * Flight : He can fly, but he no longer glows or leaves an energy trail when he does it.
 *  Dark Energy Control & Manipulation : Darkstar can now manipulate and control dark energy and display it as blasts of black energy. This is similar to Gwen's mana manipulation/control and may stem from his temporary absorption of her life force energy.
 *  Absorption of Life Force Energy : He can absorb energy using his own dark energy as a conduit which expands his list of targets exponentially. As seen in "Darkstar Rising", when he absorbs the DNAlien's powers during the fight, when Darkstar absorbs them, he also absorbs their skeleton until their skin is left. Gwen's mana shields seem to be the only defense against his long-range attacks.