% Well think of it this way. Theres no way in hell unless through direct communication with the darkness that the Vex could have access to the Black Heart, a literal artifact of the darkness. But, the Black Garden is full of Vex structures. However, if we look at present Mercury, practically all of life was wiped out and replaced with machines, as in D1 up to CoO, Guardians had never even gone on one patrol mission on Mercury. Nessus and Venus could have possibly been turned into 100% Vex territory. However thanks to Guardians and the other races that resided(Specifically the Red Legion and the Taken/Fallen on Venus and Red Legion and Fallen on Mars), they could not be 100% reformed. Theres nothing stopping the Vex from reforming the Black Garden, yet there is still an abundance of plant life on what looks practically like another machine world. I believe the Black Garden is kind of like the garden that is read about in the Bible(not trying to get all religious...just wanna make a comparison). God(the Darkness) creates the garden in heaven(Black Garden) and it has many great things inside of it, one being the Tree of Knowledge of Good and Evil(Black Heart). He tells Adam and Eve(The Vex) that they are free in the garden, but to not touch of the tree. So the Vex can freely prance around in the Black Garden, yet it is a Darkness related location, and the Darkness let's them know not to go overboard, but enjoy themselves in the garden. %

<They needed something with similar goals that gives a flying -blam!- about preserving beauty. Poof, Vex. I actually don't know and I'm disappointed in that.>

[quote]What exactly is the Black Garden? What could the Vex, a race of sentient, time-traveling, bio-organic machines Hell-bent on the termination of all life, possibly be an answer to?[/quote] Survival. The Hive behave like a swarm of locust. The Vex behave like an invasive species. That moves into an area, and then crowds out and strangles the indigenous life. What if the Vex were the creation of some OTHER form of life? Sort of like how SIVA was the creation of humans? But the Black Garden seems to be a site of communion between the Vex...and The Darkness. Where the Vex draw power from the Darkness by "worshiping" it. We had to destroy the Black Heart in Destiny 1 to allow the Traveller to heal and ultimately awaken. Whatever is in those Pyramid ships chose to use the Black Garden for its own purposes....and as a means by which to communicate with us. Whcih I believe its goals are to either tempt us to join it.....or destroy us if we wont. By offering us the same sort of Devil's Bargain that the Worm Gods offered the Hive back on Firmament.

How to stop toxic forums ....maybe.

The darkness in the garden aka the heart of the black garden was something that the vex couldn’t simulate, and that collective couldn’t think of anything else to do except worship it as a god.(which makes me wonder why none of the collectives worship the traveler) Spoilers for the Aspect lore book:[spoiler]The vex took care of the garden out of loyalty, hoping for some sort of reward for their loyalty to it.(which they did get.)[/spoiler]

What is the Black Garden? A spot in which the Vex worship the Darkness. What are the Vex an answer to? The Guardians. The Darkness, in its all-knowing power, as the Vex were worshiping the Heart, turned the Vex into Guardian killers. I can’t believe I haven’t realized this earlier, but the Vex might just be the perfect harbingers of doom. The Vex want everything in the galaxy gone and only them to remain, right? That’s not all. They want the Darkness to reign. That’s why everything in the Dark Future is, well, Dark.

I don't think it's too difficult to deduce what trans-temporal, religious, hive-minded, murderous bio-bots are an answer to. [spoiler]They're on a crusade.[/spoiler]

From the cutscene, it seems like the Vex Milk is really the Vex, it just controls the metal frames.

Existence is suffering.