Selene is Marvel's oldest living mutant, already eons old when early humans cobbled together the first civilizations. Selene has been able to sustain her incredibly long life through a form of psychic vampirism, stealing the life-force from likely young candidates to keep her youth and stunning beauty intact. Her powers also grant her considerable telepathic and telekinetic abilities. The final aspect of her mutation is her power to put absorbed life-force into inanimate objects, creating temporary minions. Using her mutant gifts drains her life-force, and she prefers to rely on her considerable magical abilities and skill as a manipulator.
Though the details of her origin and powers might throw you for a loop, Selene is still in many ways an archetypal vampire in the vein of Dracula, and is powerful enough to have taken on Magneto and Dr. Doom at the same time, and pose a threat even to super-teams as powerful as the X-Men.
Mechanics
Selene is just a bit shorter than (Zero Suit) Samus, and has a somewhat similar build, though her posture is much haughtier and more commanding. Her weight is, unfortunately for her, also comparable to Zero Suit Samus's. Though she is theoretically capable of quick movement, she would rather not do anything so undignified as sprinting (especially not in those heels), and so you'll find her ground movement and jumps to be just on the low side of average. Her ability to maneuver in the air is among the very best there is, however, thanks to her very fine-tuned control, quick lateral movement, and low fall speed.
Grab
Grab~Psychic Drain
Selene's grab range is nothing to write home about, but she is incredibly quick. Her pummel is the highlight of the move. Each tap of the button causes her eyes to glow blue, deals 2.5%, and adds 2.5% to Selene's "life-force." The extra life-force considerably augments Selene's physical abilities. A portion of all damage Selene takes equal to one tenth of the total amount of life-force she has stored is negated. The maximum damage barrier from this effect is 6%. Additionally, Selene's attacks are augmented by the life-force she's drained, which will be discussed later.
In battles with more than one opponent, this attack has an additional effect, providing Selene drains more than 50% from them (in a single stock). The afflicted fighter will, in the manner of a traditional vampire, have their pummel gain this life-force draining effect. The foe, however, will be dependent on the life-force they drain; when they have no absorbed life-force they will take damage at a rate of 7% per second. They also gain the same damage negation that Selene does, as well as a slight speed boost on all attacks and their dash. Life-force held by an afflicted opponent will dwindle at a rate of 7.5% per second, unless they are within four Stage Builder Units of Selene. Attacking Selene will cause the afflicted to take 1.2x as much damage (though no knockback) as they deal to Selene. The afflicted are also unaffected by all of Selene's specials, though that protection ends as soon as they attack Selene. When a fighter respawns, their affliction is cured.
Life-force does have a visual indicator; after stealing some, Selene will glow with a faint blue aura. The more she drains, the larger and brighter the aura gets.
Specials
Neutral~Psychic Blast
Selene's eyes turn bright blue for a moment (see the top left picture in the above montage) as bolts of black energy erupt from her head and spiral outward. The dark energy swirls around Selene's head, covering an area with a radius of one Mario-height around her head for as long as you hold the Special button, with a minimum of one twelfth of a second and a maximum of a full second. On releasing the Special button, the bolts of psychic energy fly radially outward. There are twelve Ganondorf-height bolts, each launched at angles 30 degrees apart, and they fly a distance of one and a quarter Battlefield platforms before disappearing in a poof of smoke.
Before being launched, the psychic energy will simply ensnare opponents, preventing anyone caught in it from attacking or moving as they sway back and forth, hypnotized. The actual blast deals 8% and low radial knockback. Though not an incredibly powerful attack, this move does have a wide range of utility thanks to its large area of effect. This attack is one of few unaffected by storing life-force.
Forward~Mind into Matter
With a crooked smirk on her face, Selene points forward as the stage one Battlefield platform ahead of her erupts upward, forming a pillar as tall and half again as Ganondorf, and as wide as the smallest Stage Builder Block. The pillar will last for eight seconds before it crumbles back down into the stage. There is no limit to how many of these Selene may create at one time, but the attack does leave her very vulnerable for a moment.
This pillar she creates will act solid to opponents, but will rearrange its dirt to allow Selene to pass through freely. If a foe is standing on top of the ground where the pillar is raised or jumps on top of a preexisting pillar, they'll be stuck in place atop it as though hit with a pitfall. If Selene is hit into the wall with an attack ordinarily powerful enough to cause them to ricochet, the pillar will slow Selene's momentum and gently release her on the other side of the pillar. Should this happen to the foe, they'll be pitfalled in the side of the wall.
Using this attack with life-force stored will result in a much taller pillar, twice as high as the original. Doing this drains 7.5% life-force.
Up~Shadow Form
Selene's body begins to stretch upward and blacken as she takes on the form seen in the upper left picture of the above montage. In this shadowy, elongated form the player can tilt the analog in any direction to send her gliding that way. The 'flight' lasts for four seconds before Selene's shadowy tail, which stretches all the way back to the point where she first used the move, races along its length and catches up with her head and shoulders to form back into Selene's body. Hitting Selene's head will knock her out of this stance, but missing and hitting the shadow will have no effect.
Anyone who touches Selene's shadow tail will be stunned and slowly dragged along it to the point where Selene reforms, depositing them in the clutches of her grab. Fighters can DI out of the slipstream, but it's no easy task, especially if they're caught in it closer to Selene. If multiple fighters are caught in the tail, the one closest to Selene will end up in the grab, while the others will be blasted away by a burst of blue flame that deals 15% and high radial knockback.
Selene cannot use most of her attacks while in her shadow form, but she can use her Neutral Special by pressing either attack button, or cancel out of the maneuver by tapping Shield. If Selene drags a foe into a pillar with this move, they'll be pitfalled in the side of it through the end of Selene's move (and for the normal amount of pitfall time afterward), and won't be dragged into the grab at the end of the maneuver.
This attack may only be used once per air trip but never leaves Selene in helpless. If Selene has life-force stored, contact with the shadow tail will deal passive damage equal to one third of the total amount of life-force stored per second, to a maximum of 14% per second.
Down~Dust to Dust
Crouching, Selene places one hand palm-down on the stage, and blue-black energy begins to spiral in toward the point of contact from the area around it. As she's doing this, any pillars within a Bowser-width of Selene will crumble to dust and disappear, as will any items or projectiles that enter the same radius.
If Selene has life-force stored, using this attack will burn through it at a rate of 15% per second. However, this life-force doesn't just go away; it heals Selene at a rate of 10% per second.
Throws
Forward~Shadow Rush
With the foe in her clutches, Selene changes to her shadow form as she blasts forward at Sonic's dash speed. The foe retains the escape progress they made during the pummel portion of the grab, and the move won't end until they escape, something hits them, Selene embeds them in a pillar or Selene reaches the edge of the platform and deposits the foe. When the foe is released (no matter how), Selene will retract her body along the shadow tail and wind up back at the point where she used the grab.
Back~Dismissal
Selene simply casts the foe aside, tossing the foe behind her on a trajectory that remains perfectly horizontal for at least a Battlefield platform's length. The attack only deals 3% and so has poor knockback growth, but the throw does get the foe's speed up just enough to embed them in a pillar at short distances. A good way to punish a foe who manages to get behind you or simply get someone out of your hair for a while.
Up~Foolish Mortal
Once again taking on her shadowy form, Selene blasts her victim straight upward, dealing 9% and moderate knockback, as she expands into a shadowy mass twice the size of Bowser, with only her head visible at the very top of the cloud. She only holds this form for a moment before shrinking back down, but anyone who touches her shadow will be sucked in and trapped in a grab. This is particularly useful when trying to suck the life out of a foe and another fighter tries to run in and take advantage of your distraction, though it requires careful timing to properly use it as a counter. Bear in mind that in this attack, as in all her other shadow form attacks, her head remains vulnerable.
Down~Dine and Dash
Selene's eyes briefly glow blue, and the foe is smashed downward into their prone state for 8%. Selene immediately vanishes, shrinking down into a microscopic shadow, and reappears atop the center of the highest point on the stage (pillars included). The animation of her reappearance is her disappearance animation in reverse.
Smashes
Though using Smashes does not drain Selene's life-force, they cannot be charged unless Selene has at least 7.5% stored.
Forward~Darkforce Flow
Selene reaches forward with one hand that promptly turns into a thin shadowy tendril and races forward at the speed of Fox's lasers. The tendril will reach through all stage hazards and walls, only stopping and dissipating (leaving Selene's hand intact, of course) when its tip reaches two Battlefield platforms' length from Selene. If a foe is hit by the tendril's tip, they'll take 10-14% and be weakly smashed downward. Foes who collide with the side of the tendril will be dragged along its length at the speed the tendril is travelling. This attack can be angled up or down.
Up~Animation
Casting one hand forward, fingers splayed and palm downward, Selene causes a Kirby-sized stone (or whatever the stage is made out of) fist to erupt from the stage in front of her. The fist reaches upward a Mario-height and deals 16-22.4% and strong upward knockback. Besides being Selene's strongest kill move, the fist lingers for about half a second before crumbling, acting as a barrier and a platform for Selene. If a foe tries to stand on a fist, it will immediately crumble, causing them to briefly tumble as if footstooled before regaining control. Like pillars, fists can be used to corral foes, albeit in a far more temporary way.
Down~Pyrokinesis
Selene scrapes one heel against the stage, throwing up a cascade of sparks which quickly erupt into blue flames that cover the stage within one and a half Stage Builder Units of Selene. Anyone who touches the fire will take 12-16.8% and low-moderate knockback. The flames do not affect Selene or foes, and last for two seconds.
Standards
Using Standards does drain Selene's life-force by the amount of damage the attack deals, and the attacks all receive a 2% damage bonus (not deducted from Selene's life-force) and minor reduction in start-up if Selene has more life-force built up before she uses the attack than the attack drains.
Jab~
Selene snaps her fingers and a blue fireball similar in appearance and animation to Din's Fire but half the size materializes just in front of Selene, dealing 7% and low radial knockback.
Forward~
Selene points forward and a line of blue fire emits from her finger and stretches forward a Stage Builder Unit before separating from Selene entirely and shooting forward a Battlefield platform's length. It deals 6% and drags foes to the end of its trajectory before disappearing. It can be angled up or down.
Up~
Selene coats her hand in blue flame and thrusts it straight upward, dealing 8% and sending foes diagonally upward with a flame effect. The flame is about the size of a purple Pikmin, making it a fairly large hitbox, especially considering the fact that it travels from nearly the stage all the way to the top of Selene's reach.
Down~
Selene brushes one hand along the stage, ending with her arm extended almost straight forward, creating a ripple in the stage that travels forward at Sonic's dash speed, dissipating after travelling forward 2.3 Battlefield platforms. If it hits a foe, they'll take 5% and trip.
Dash~
Selene stops dashing as she brings one leg up and executes a spin kick that deals 11% and strong knockback.
Aerials
Using Standards does drain Selene's life-force by the amount of damage the attack deals, and the attacks all receive a 2% damage bonus (not deducted from Selene's life-force) and minor reduction in start-up if Selene has more life-force built up before she uses the attack than the attack drains.
Neutral~
Selene crosses her arms over her chest, then flings them out to her sides, sending a ring of fire outward in all directions. The fire deals 4% and pushing the foe to the edge of its range, half a Battlefield platform away from Selene.
Forward~
Selene performs a simple sex kick that lasts slightly longer than most, and deals 8% then 5% (The attack only drains 8% life force). The kick directs foes downward if it hits after the initial thrust.
Back~
Selene half-spins and kicks out with one leg for 8% and light knockback. A thin jet of flame spurts out of the tip of her foot and extends outward two SBUs. It lasts only as long as the kick does, and deals 13% damage and high, mostly upward knockback.
Up~
Selene executes the dreaded flipkick, albeit a slightly fiery one than usual, dealing 8% and light radial knockback.
Down~
Selene changes into her shadowy form and dives straight downward at Sonic's dash speed five Ganondorf-heights. Everyone she hits along the way is sent sailing diagonally upward with 11% and a blue fire effect. At the bottom of the dive, she takes her human form on again as her falling speed returns to normal.
Final Smash
Selene has the Smash Ball! She uses its power to ascend to godhood. She steps into the background and out of the fight as her skin turns a deep blue hue and the air takes on a tint to match. As she steps back, a golem made out of the same material of the stage rises up out of the place where she used the Final Smash. The golem is twice the size of Ganondorf, and has similar proportions and the same moveset, albeit at double the power level. You are now free to control this golem, which is utterly invincible. Ganondorf's not fast enough to chase down your foes? Don't worry, there are about five or six other golems controlled by Level 8 AI working with you. They're not brilliant, but they should be able to at least slow the foe up enough to let you get some hits in. After ten seconds, all golems explode with the power of a Bob-Omb and Selene returns to the stage.