Supergirl is the Girl of Steel and the cousin of Superman. Besides sharing a bloodline, the two have several more things in common. They both survived the destruction of Krypton, and they both have starred in their own movies and have been featured on their own TV shows. Finally, it's inevitable that they would face off with the same enemies from time to time.
Any Superman villain Supergirl may have beaten in the past will most likely be out for revenge at some point, so here is a look at five Superman villains Supergirl can defeat, as well as five that she would struggle against.
10 CAN DEFEAT: Prankster
The Prankster is one of Superman's oldest foes. As his name implies, he uses practical jokes and related gags to commit his crimes.
Over the years, the Prankster has received an upgrade in the tech he uses. While that may make him a danger to lesser powered beings, he's still no match for someone with the powers of Supergirl. Anything short of a whoopee cushion filled with kryptonite just isn't going to cut it.
9 WOULD STRUGGLE AGAINST: Metallo
Speaking of kryptonite, one Superman villain Supergirl would definitely struggle against is Metallo. Metallo is a cyborg that has a kryptonite power source in his heart and has given the Man of Steel a run for his money on numerous occasions over the years.
Besides the kryptonite powering him, Metallo has enhanced strength and speed that puts him on par with Superman. In addition, at one point he also had the ability to grow to giant proportions. A giant super-strong cyborg with a kryptonite heart is definitely an opponent Supergirl would struggle against.
8 CAN DEFEAT: Bizarro
Hailing from the Bizarro World, Bizarro is the exact opposite of Superman. While they share some abilities like super strength and flight, Bizarro is Superman's opposite in most other instances. Instead of heat vision, Bizarro has freeze vision; in turn, he has flame breath instead of freeze breath, etc. He is also vulnerable to blue kryptonite instead of green.
Bizarro's powers make him a force to be reckoned with, but Supergirl can defeat the villain by outsmarting him thanks to Bizarro's limited intelligence. She may not even need to fight him if she's able to convince Bizarro that they're friends...err, enemies in this case.
7 WOULD STRUGGLE AGAINST: Doomsday
Doomsday killed Superman once upon a time. That alone would make defeating Doomsday a struggle not only for Supergirl but for any hero that crossed his path.
The ultimate killing machine, Doomsday is a mindless monster with nearly immeasurable strength. For Supergirl to have any sort of chance at defeating Doomsday, she couldn't hold anything back and would have to use every ounce of her strength. Even then, it might not be enough.
6 CAN DEFEAT: Toyman
A few different men have been known as Toyman over the course of DC's history, with the most well-known being Winslow Schott. Toyman has incredible technological expertise, with a specialty in robotics. He uses his skills to make deadly toy-based gadgets and devices in his villainous schemes.
Despite Toyman's technological skills, there isn't a device he can build that's strong enough to beat Supergirl. Once Supergirl gets past whatever robot Toyman may throw at her, it's just a matter of time before Supergirl carts Toyman off to jail.
5 WOULD STRUGGLE AGAINST: Brainiac
A genius-level technology-based Superman villain, Brainiac would prove a hard test for Supergirl. It's actually insulting to call Brainiac "just" a genius, as the villain possesses a twelfth-level intellect. Besides his vast intelligence, Brainiac has a powerful ship at his command and, thanks to genetic and cybernetic enhancements, he is also as strong and invulnerable as a Kryptonian powered by a yellow sun.
With plenty of brawn to back up his virtually unparalleled intellect, Brainiac is a foe many would struggle against, and Supergirl would be no different. While Supergirl can never be counted out of any fight, outside the box thinking would be her only chance at coming out victorious against Brainiac.
4 CAN DEFEAT: Livewire
Livewire is a unique Superman villain. Just like Harley Quinn, Livewire started off in the DCAU before appearing in the comics. A popular character from Superman: The Animated Series, Livewire has also made live-action appearances on Supergirl as well as Smallville.
As a villain, Livewire is electric – literally. A being of pure electricity, she is able to absorb immense quantities of electricity as well as transform her entire self into living electricity. Despite her impressive powers, Livewire has a glaring weakness to water. Assuming Supergirl doesn't have access to a hose, Supergirl can take Livewire down with a combination of her freeze breath and heat vision.
3 WOULD STRUGGLE AGAINST: Darkseid
While Darkseid poses a significant threat to the entire DC universe, he also falls under the category of a Superman villain. And he is without question one of the most powerful villains Superman has ever faced.
Supergirl has faced Darkseid in the past and was able to walk away, an impressive feat in and of itself. However, any hero – Supergirl included – would struggle greatly against the ruler of Apokolips and would be advised to bring (lots of) back up with them.
2 CAN DEFEAT: General Zod
As if having all Superman's powers weren't enough, General Zod is also a brilliant military tactician. Supergirl's relationship with Superman instantly puts her in the crosshairs of the evil megalomaniac.
While the fight would be very difficult, Supergirl does have one distinct edge over General Zod. Being imprisoned in the Phantom Zone for many years, Zod hasn't had the exposure to Earth's yellow sun that Supergirl has, making his powers inferior to hers. With her superior powers as well as her experience in their use Supergirl would ultimately come out on top against Zod.
1 WOULD STRUGGLE AGAINST: Lex Luthor
On the surface, Lex Luthor is no match for Superman or Supergirl; however, what Lex lacks in superpowers he more than makes up for with cunning and intelligence. Lex Luthor is known as the most intelligent man in the DC universe. Even Brainiac respects Lex's intelligence. Among many of Lex's genius inventions, he's created a battlesuit that has the power to take on Superman.
Whether in his battlesuit or not, Supergirl would struggle against Lex because his intelligence puts him ten steps ahead of everyone else. One wrong move is all it would take for Lex to come out ahead.