I really think that TwiLuna makes more sense as a ship; I get a creepy mother-daughter vibe with TwiLestia;
This, in my mind, is one of the prime reasons why I despise characters who play evil in a good party. Simply put, doing evil things just "for teh evulz" doesn't make sense in character or in game. Sure, if I'm DM-ing, you can walk into town hall, shoot the guards, murder the mayor, and then walk out. But please don't do it for no reason. Maybe the mayor offended you before, or he has some information you want suppressed. But give me a reason. Don't just kill people "because I'm evil." Evil, in my mind, is just a normal person with a larger idea of what is acceptable. If killing someone will not profit you, don't do it--no matter what the alignment.
Well, one of my headcanons is that Derpy is actually a genius almost on par with Twilight. The reason that she's somewhat awkward both vocally and physically is not that she's stupid or handicapped--it's because she takes in so much more than she can process at once.
Now I want to breed them just to see what happens.
Well, here's my OC's alignments.
Dive Bomb is an idealist at heart. He believes that knowledge, properly applied, can solve any problem. He started out as neutral good, but continued exposure to the evils of the world, combined with his experimentation and manufacturing of WMDs has pushed his alignment down to True Neutral. (The destruction of Canterlot, as well as the many civilians living there, has not been good to his mental health--ultimately, the sale of bombs was only a means of getting the money necessary to fund his research on immortality.)
Color wise, he would be Primary Blue, secondary black. His primary quest is knowledge and making the world a better place. However, if he's able to achieve immortality/godhood on the side, so much the better.
Blunt Trauma is a dependable butler, for all that he's a patchwork attempt at creating an artificial alicorn from reassemble corpses. Not much can take him away from his voracious reading and caring for his family. Despite having been created by the young Dive Bomb, he still plays a father role for the young scientist, and grandfather for DB's daughter Athena. In my mind, he comes across as Lawful Neutral. He was assembled as a fully-grown alicorn stallion, and so feels a voracious need to learn more about the universe. According to the color system, he is White with a secondary of blue. He has watched Dive Bomb's slow descent into the deeper depths of madness with worry, but still supports his creator in his efforts to become more powerful.
Athena was an attempt at self-cloning where a mistake was made. She's yet to discover what it is that she wants to do with here life. She is the purest part of the team, playing a sweetly snarky Neutral Good. She is a creature of simple emotions, being a Red aligned pegasus filly.