R-Type/Fridge

Fridge Brilliance

 * It's not likely the Bydo are constraining themselves to attacking just the 23rd century and its immediate vicinity. Why not attack the far past, while you're at it? Oh, right, they probably have. Made from the vilest potentials of the human psyche? Meet the Legions of Hell...

Fridge Horror

 * The Bydo from R-Type. They are essentially the embodiment of the most evil elements of mankind and run off of mankind's most basic instincts. And they're Exclusively Evil, being completely incapable of being redeemed or even reasoned with. And that's not even mentioning its properties: they exist in a flux between matter and energy and can turn into a wave form. This means they can turn into a wave, bypass pretty much any form of protection, turn back into matter and begin The Corruption. In the second ending of Final, you get corrupted and fight against your former allies without realizing that you've been corrupted by the Bydo.
 * That's not even the worst of it. How did these horrible beings come into existence? 26th century mankind deliberately built them that way, to serve as biological weapons against other solar systems (the Bydo became Phlebotinum Rebels and humanity was forced to blast them into Another Dimension to keep from getting wiped out). This brings up two possibilities: 1. Future humanity was fighting an enemy so unbelievably horrific that the Bydo were seen as an acceptable weapon to use against them, or 2. Future humanity was bent on wiping out other species with the Bydo, which would seem to indicate that they haven't much left in the way of morals themselves...
 * Beyond the Bydo themselves, there is this question: exactly what kind of horrific enemy was future humanity fighting that they thought the Bydo were an acceptable weapon?
 * Bitter Chocolate answers this. There's an "Other Civilization" and they apparently manage to do something that make the Bydo do a 180. Let's just leave it at that.