Gonna make a little backstory here
A strange feminine figure stood in front of the viewing screen, decked out it what appeared to be a light blue flight suit with silver plates on its chest, shoulders, and shins. Its eyes were slanted at a 45 degree angle and its irises were the color of blood. Her features were sharp and the body was thin and long by human standards, her height reaching a good 6'5". Her hair was feathery like a moth's antennae and the long 'stalks' reached down to her waist, which moved despite there being no air flow on the command deck.
"So this is the so called unconquerable planet. Such a delightful blue gem, if I am able to capture it for the patriarch I am sure I will generously rewarded and he will look at me with those strong eyes of his..."
The alien shivered in delight for a moment, before giving a small cough to gain hold of herself.
"Thankfully we have been preparing our forces for a long time despite the barrier it will only be a matter of time before we can crush any resistance!"
She put a hand out and made the motion of grabbing the visual of the planet in front of her, her fist clenched with great strength. There were two main reasons the planet was such a hard location to conquer: One, there were a lot of strange individuals with strange powers on that planet, ranging from the mundane to the fantastical who could put up a proper fight. Two, there was a strange dimensional barrier around the planet that was specifically designed to keep out alien forces, while not affecting the inhabitants in the least. Because of the barrier they would have to expend a great deal of power every time they sent something down, which limited the amount that could be sent.
As the barrier prevented any large invasion forces, that meant they would have to send down quality instead of quantity. To help facilitate her plans to capture the Earth and shut down the field protecting it, the alien had gone into the business of Monsternacy, a scientific and magical fusion technique to create powerful, and often very unique, fighting machines. Aside from that she had also placed a bounty on the barrier maker to try and entice some of the galaxy's most fearsome mercenaries. She could get the best of all worlds with her schemes.
Soon it would be time to start the conquest of the Earth. Buzzing a little tune she skipped along off the command deck to head down to the Monsternacy department to see what dastardly monster she would send down first.