The Old Ones, or the Parents, are above the 13 Bloodlines. They are the unofficial but true heads of the Illuminati. There are only about twenty of them; it is not known how many there are due to the extremely high level of classification. 
They can go into stasis and skip over 300 years at a time if they want. They do this by going into something that looks like a sarcophagus. 
The whole process of how they extend their lives requires a vampiric process. They need to feed on other people, but they do not drink blood. That's not their real method. Their real method is a lot more grotesque. That is just a legend the Cabal made up to hide their real method. Their real method is far more grotesque. In fact, each of the Old Ones seems to have their own technology.
The victims must consent to this process. To do this, they approach people who are in secret societies like the Illuminists or the Masons and they tell them that they've been there since the time of Atlantis, and they'll do things like cut their hand open and show the victim it closing up again. They will also show you advanced technology. They'll show you incredible things. They have spaceships and stargates, and they'll take you to bases on other worlds. They'll show you whatever they can to get you interested in helping them. They'll say I need you to help me because I'm here to guard over the planet and watch over it and make sure everything goes the way they want it to go.
The death is horrible once a victim consents, so they try to get it over with quickly.
They also have groups that help coordinate. This is before the 13 Bloodlines. Family masters is the highest level. Then trustees then operatives and there's a large amount of those. There's only a small number of the other two groups. Before that is the 13 Illuminati bloodlines called the Fathers and/or Houses. 
Some of these people are over 13,000 years old.
You kill them by separating the brain from the spinal column. This is depicted in Highlander. In Jupiter Ascending, there is a ruling caste of interplanetary humans who use this liquid that they bathe in that's made from human beings. That's how they rejuvenate themselves and stay perpetually young. 
They don't have a metal chassis like Wolverine. Some of them look a little different because they come from previous human civilizations that have since left the Earth. They look human, but their eyes are really strange. One kind of looks Asian, but doesn't look like anybody we see. Some of them have eyes that are a little bit too big. 
Some Draco made deals with people on Earth to give them immortality. Their metabolism becomes super-accelerated which is almost like a time-stasis field in their body. It also is a super-healing power.