In the final saga of Dragon Ball City, the dark dragons, born from the negative energy accumulated by the dragon balls, emerge as the last enemies. The most powerful, the evil black smoke dragon, created seven others. The two-star dragon represents pollution but is weak; Pan defeats it with ease. The five-star dragon, representing electricity, has strong defenses but is defeated by Goku's kamehameha. The six-star dragon, a sea princess, is also easily defeated by Goku. The seven-star dragon absorbs beings to gain power but is ultimately defeated by Goku and Pan. The four-star dragon, representing fire, is powerful but loyal and not truly evil. It is killed by the one-star dragon, which is then defeated by Goku's enhanced phase 4 power. Omega Shenron, formed from the one-star dragon absorbing the other dragon balls, becomes the ultimate enemy but is eventually defeated by Goku with the help of energy gathered from the universe.
Here are the key facts extracted from the text:
1. The "Evil Dragons" or "Dark Dragons" are a group of powerful enemies in Dragon Ball City.
2. The Dark Dragons were born from the excessive use of the Dragon Balls and the accumulation of negative energy.
3. The first Dark Dragon to appear is the Evil Black Smoke Dragon, which is the negative part of Shenron.
4. The Evil Black Smoke Dragon is the most powerful of the Dark Dragons and created the other seven.
5. The power of the seven Dark Dragons together makes the Evil Black Smoke Dragon extremely powerful.
6. Only Goku in Super Saiyan Phase 4 can defeat the Evil Black Smoke Dragon.
7. The Dark Dragons are:
* Two-Star Dragon (represents pollution)
* Five-Star Dragon (represents electricity)
* Six-Star Dragon (represents water and wind)
* Seven-Star Dragon (represents earth)
* Four-Star Dragon (represents fire)
* Three-Star Dragon (represents ice)
* One-Star Dragon (element unknown)
8. Each Dark Dragon has its unique abilities and weaknesses.
9. The Four-Star Dragon is the only loyal Dragon and has a good heart.
10. The One-Star Dragon is the most powerful of all the Dark Dragons.
11. The One-Star Dragon's power grows exponentially after eating the rest of the Dragon Spheres.
12. The Omega Shenron is the final form of the One-Star Dragon and has the power of the seven Dragon Spheres.
13. Omega Shenron is the most powerful villain Goku has faced in his life.
14. Only a special fusion of Goku and Vegeta in Super Saiyan Phase 4 can defeat Omega Shenron.
15. The energy of the entire Universe 7 is needed to defeat Omega Shenron.