So, why should anybody pay 13 points to get a powerful enemy?
It’s like setting up a free advancement scheme for your stats and skills.
And possibly getting a free helpful relationship in the bargain!
First, adversarial is not necessarily the same thing as an enemy. It just means they often work against your interests.
Second, spending the points gives you the ability to work with the GM to define the character and his relationship to you. In essence, you’re buying some control over the game’s setting.
Third, spending the points gives you the power to call for a scene with the character whenever it makes sense. You can pop in and talk to that character. Now sure, if that character is an enemy whose only goal is to kill you, that may not be so useful. But if the character is a powerful political rival, for instance, it could be really useful.
If you’re familiar with The Three Musketeers, a perfect example of a 13 point relationship is d’Artagnan’s relationship with Cardinal Richelieu. Richelieu is bad news. He has agents everywhere who are willing to pursue his agenda by whatever means necessary. He would not be discomfited if his agents eliminated d’Artagnan and his friends permanently. But neither is he particularly interested in d’Artagnan’s death. On occasion, d’Artagnan is even useful to him. Our hero even up winning a lieutenancy in the musketeers as a result of the relationship. It ends up being very useful, even if it causes great difficulty as well.
The King may hate you, but you still have the ability to bring the King into play any time you want and that is powerful.
It is also the difference between being Robin Hood and being the third Merry Man on the left. The king knows your name and cares enough to have an opinion about you. Some games you work up to those levels. Some games need to start there and you pay your 13 points for the privilege.
It allows you to basically tell the GM who you want the villain to be.
Darth Vader - Very Important, Hateful, Family
Lol.
Some reasons:
- Know your enemy, he’s something you created, you actually want in the adventure.
- You start the adventure with a clear, (metagame)obvious opposition, and a hand-made, personal hook that suits your idea of character.
- It’s kind of a artha generator if you tie him to your BITs.
Stay cool 
Voldemort!
How dare you speak his name? ¬¬
“Yes Harry, it is I, Lord Voldemort, in disguise, again!”
Someone link to the Shyaporn video… I don’t have access to youtube right now…
Very nicely put!
Too bad cannonballs have such a high VA.
Adversarial relationships are a great way to drive play. In one of my games the amount of grief I got from my PC’s father and brother to help them survive a famine was stupendous, and in the end, it helped me fulfil a belief.