What I mean by this is that SIVA as a unique type of self replicating material,Nanite,augmentative machine, and yes even a form of power source as it seems capable of generating energy on its own. With this said these are the reason why SIVA now that's been unleashed will never leave 1. As it already has its hooks in the Fallen Devil Splicers it will likely spread to other Houses given time. 2.SIVA infects the land and continues to replicate even after we destroyed the replication plant it still continues to exists. 3. It can theoretically run forever as the Raid Armor states therefore centuries could pass and a single drop of SIVA is still viable. 4. Nanites infect everything even those that are around it still have it clinging to their clothing and SIVA is definitely not an exception as shown in the Grimoire Cards and the Intro cinematic making it a perfect form of vector to spread into unforeseen areas. 5.It can influence all forms of life not just the Human,Awoken,Exo,Hive, or Eliksni it can and most likely will spread to the other factions in a virulent manner. 6.SIVA as a whole is something that can't be eliminated or controlled as its always growing and seems to evolve as well. Frankly the huge plot hole of how SIVA didn't continue spreading unchecked is a mystery as it is "self replicating" meaning it can use any material around it to make more of itself therefore meaning that the replication chamber only add newer original strain SIVA then the newly grown version which only means it should have spread far beyond the Plaguelands and deep into the cosmodrome. 7.As weapons such as Gjallarhorn,Outbreak Prime and the raid weaponry/armor use SIVA as the building blocks of the weaponry SIVA has theoretically already infected everything around these weapons by mere proximity even if the SIVA was reprogrammed to work in these weapons it means it would still follow the directives its given without end. Meaning I say "Build,Repair, and Enhance" the SIVA will take the meaning literally and branch off the said weapon and build and repair along with enhancing everything it comes into contact with. 8.SIVA is the only way the Fallen as a species can survive now. We have murdered almost all the Prime servitors in the other major houses and I doubt the house of Kings have 4 Prime servitors lying around to produce that much ether. As SIVA can make artificial ether as shown in collection patrol missions it means SIVA will be the only way for themselves as a species to grow and reclaim what they lost without the use of the Prime Servitors. 9.SIVA will spread unchecked whether we like it or not by simply the devil splicers mere presence sending the stuff out off their very bodies. Meaning they have already seeded Mars, the Moon, Earth and quite possible Venus as well meaning even if we have eliminated it on earth it has 3 or 4 more planets to grow unchecked on. 10. The only way to annihilate something so small as a nanite would be to either a completely annihilate the atomic structure of the surrounding area leaving nothing but a carbon hole in the ground and not even a single nanite left or a large scale EMP but SIVA may be resistant to that as shown during the Iron Tomb mission it can absorb a lot of energy and only merely temporarily shutdown.The other problem with this is that SIVA is airborne meaning all it needs to do is take a nice wind current and its dispersed everywhere. Hope this adds a bit of interest to everyone for Destiny 2 thinking.