"Death of the Dragons" deals with the death of several metaphorical dragons - the alien dragons inside the Earth, the collapse of the old national states and maybe also the end of humanity as we know it. Change is in the air, and it is up to everyone to decide for his or herself how to react to it.
The basic idea is that the player characters become infected with the dragon plasmids by drinking champagne (or maybe, if that solution feels a bit too romantic or weird, by going too close to a blowout of oil or venturing into a really deep cave). After a while they will start developing odd powers, which may or may not be useful for their everyday life. What happens then is up to them.
One thing often ignored in superhero stories is how forces are acquired; not the source of the powers but how the heroes learn to use them. In this campaign I instead let the players explore how it felt to gradually discover new powers, not knowing their limits or possibilities, making up theories of how they work, why and what they could be used for.
The power level can be kept quite low - the genetic powers are profound but slow to work and at the beginning not very deadly. At the same time, allowing the players to increase their powers by experience is very rewarding. Make it cheap to develop them (I gave them dots for free sometimes, and allowed a very low experience point cost for developing them) and watch how they start to develop themselves. Then slowly sneak in the side effects - the powers amplify their subconscious self-images, making them less and less normal and more and more self-defined posthumans. At the same time the power of the dragons in their lives will increase: accidental trances, odd changes, even instances of possession. In the end they will be faced with the realisation that their powers do have a hefty prize - if they go too far (and they may already have done it) they will lose their humanity and possibly become little more than interfaces for the dragons.
At the same time the outside, mundane world is bound to play a role. If the players try to exploit their character's powers, they will be busy dealing with non-hosts (who can be quite competent in their own) or rival hosts. And if the secret of the roots start to come out, many groups will begin to hunt for them and the characters.
The powers of the roots are best played as intensely personal, idiosyncratic and visceral. They are feelings, smells, intimate bodily changes. To use them the characters need to tell the GM what they do, what they think or feel, they cannot just be turned on like a technological tool. Especially the visceralness of the ability of modifying others should be played up - to change somebody they need to exchange bodily fluids of some kind - and sensing will be just as intensely emotional as reactions to body odors and personal "chemistry".
The collapse of the old: both the real dragons in the ground, the Chinese dragon and old national states are dead or dying. The old structures are breaking down, to be replaced by a new order - or chaos. How long will the current situation remain?
The price of power: the roots of the dragons enable fantastic and terrifying feats, but the more hosts rely on them the more vulnerable they become for mutation and uncontrolled change. Maybe this is not so bad, if a successful accomodation can be made.
Nationalists vs. internationalists: the conflict is about much more than money or power, it is the struggle between two ways of viewing humanity. Are we functions of the collective, created by our history and culture, or are we totally free to define ourselves arbitrarily?
My Own Campaign: Black Lotus
I ran a campaign based on giving the roots to a group of totally unlikely hosts: a gang of small-time fixers/criminals from the bad part of Chunqing. It began when they were celebrating a successful scam, where they had (on the order of one criminal gang) "redirected" a cargo intended for one of the Chunquing crime bosses. Beside the real cargo they found a bottle of champagne, which they helped themselves with...
The real story was that a Cantonese triad leader had aquired two bottles of the champagne, not knowing their abilities. After drinking one with his girlfriend, he sent the other as a gift together with the first installment of a major weapons smuggling deal to a colleauge in Sichuan.
The player characters got involved with the complex world of Chunquing semi-criminal politics while they slowly discovered that they were developing odd powers. After a too successful theft of drone weaponry made them hunted by every fraction of the republic, they decided to leave for a safer place: Canton.
The campaign continued with the development of their powers, their struggle against the Cantonese triad, their shaky alliance with the leader's girlfriend (who had her own ideas) and later their escape to Djakarta. They went from being complete nobodies to the worlds most feared biotech terror organisation, Black Lotus (a name which actually referred to their old restaurant in Chunquing). Finally they confronted NERD, the Long View and other internationalist fractions very much interested in their powers.