Alicorn gives you wiiiiiings.
Earth Pony Magic:
Starlight is stronger and tougher than most pegasi or unicorns, and is capable of using her magic to encourage a bountiful harvest from any crop, even in the most inhospitable environments.
Capable of fine manipulation, as well as lifting just about anything practical (such as a dinosaur or a meteor). Can be used to deliver telekinetic blasts.
After studying Oxy's "Instant Transmission" technique, Starlight is now capable of teleporting anywhere she's seen, without regards to distance, including back to Equestria.
As she may be called upon to battle beings that can sense magical energy, Starlight has learned a technique to mask her true power levels to keep her cover from being blown.
After some training, Starlight is now capable of sensing ki energy as well as magic, and quantifying a target's power level.
A simple force field technique, used primarily against energy blasts or being slammed into a mountain.
A blast of magic energy from her horn. Strong enough to take care of most lower-level threats easily.
Overloaded Magic Laser:
Starlight is capable of firing a more powerful magical laser by firing it without any regard for her own safety. Under normal circumstances, this does not harm her significantly, but under duress is could cause her some damage.
Starlight rapidly fires a series of Magic Lasers at the enemy.
Advanced Stun Blast:
An advanced blast of magic energy that stuns her foe, typically for live capture or to take a rogue element out of a fight. This is both her most powerful attack, and her primary one - being a pony, she doesn't want to kill her opponent if she can help it. After training for a year, she is now capable of knocking out strong targets fairly reliably for several hours.
Unable to come up with a better name at the time, Starlight named this technique after the dragonballs. In reality, the only similarity is that it's a giant sphere (or ball) of violet-pink energy thrown at the enemy. This attack concentrates her power, making it her most powerful attack, but it is more easily dodged than her other attacks.
Starlight can use this spell to find whatever she needs to, as long as she is passingly familiar with it. This includes temporal distortions.
Starlight is capable of using Hayscartes' own study method to insert herself into a book or a computer and learn things from it more efficiently. She used this spell off-screen during the time skip to study as much as she could about this world.
After studying Oxy's Kaioken technique and training in the gravity chamber, Starlight has mastered this ability insofar as she can now use it at will for a power boost of 10x, although is still only lasts for a few minutes before fading away. Starlight overloads her magic reserves, granting her a major boost in power. In this form, her eyes glow pure white, and her power level increases tenfold. However, she can only keep this form up for five to ten minutes before it burns her out.
Spoiler: Starlight's Rainbow Power Form
Spoiler: Future-Past Plot Spoilers
This form is achieved by Starlight bonding with the Element of Magic after [even bigger spoilers].
While many forms give the user a flat power boost, this form's power is dependent on the bonds Starlight has forged with others. It's typically a smaller power boost than other fighters' super forms (~40x), but it can be more if she has the will of the people behind her, working towards a common goal. Conversely, if her bonds with others break, or she acts in opposition to her friends, it drops dramatically, even potentially becoming inaccessible. She absorbs this power from others, much like a living spirit bomb or Hearts Beating As One (shouldn't that be an Undyne Cosplay ability?). Her technique makes up the differences in power levels.
In addition to receiving a power boost, Starlight shares a portion, approximately 25% of it, with her allies. Her power can be focused into cleansing corruption from a foe, granting her the following ability.
Rainbow of Light:
Starlight focuses the Element of Magic into a rainbow-colored beam of energy. This attack does not damage the foe, but it directly attacks various forms of corruption, including anything that violates the target's natural state of harmony. This can include possession by a foreign entity, or a corruption of the target's natural state (mind control, etc). This ability may fail on particularly powerful forms of corruption. [A/N: This ability is basically a deus ex machina, and should be used sparingly.]
In this state, Starlight's mane and tail grow ethereal, with a stripe of gold running through the brilliant nebula they now resemble as they whip violently in an unseen wind. Her cutie mark becomes animated as well -- the shields multiply, and the pawprints appear and disappear as though being left by an invisible puppy, scampering about on her rump. It does not yetgo much beyond her rump though, and certainly not down her legs or neck.