Okay, read closely-
First line of the post has a mistake. It says "riddle #1" instead of "riddle #11"
"I rest in a place where the tree sap is of blood."
Trees. There are none. No normal tree can bleed. So it rests in no place on Earth or Venus.
"My mark is forever, always unheard"
Forever is a long time. Infinitely marking anything that is marked. No normal being can do this.
"I appear in your dreams, but reside in reality"
Again, abnormal. The dreams of gods can do this, but this is no God.
"IT has power over my master, but my master thinks me lesser, lesser than the roses which grow forever, backward."
IT referring to the dreaming God, which thinks of <subject> minuscule. This dreaming God goes undisturbed usually, yes?
"Where you see justice, I see murder"
Where 'you' refers to us. The players. Guardians.
Okay, let's break this down-
Legends and mysteries. Legend: The Black Garden.
"I am Pujari. These are the visions I have had of the black garden"
If we are to assume that Visions are dreams, that would show where <subject> appears, since it says it appears in dreams. Your dreams, guardians dreams, Pujaris Dreams.
"The traveler moved across the face of the iron world."
This iron world is Mars. The black garden is in Meridian Bay, Mars.
"The garden grows in both directions. It grows into Tomorrow and yesterday. The red flowers bloom forever."
Back to line 4 of the riddle. IT says <subject> is insignificant compared to the roses that grow backward, forever. If we are to assume
That <subject> does rest in the black garden, then it must live specifically in the 'past' side of the black garden. In yesterday, since the flowers would grow backwards in the past. The red flowers referred in the Legend would be roses, which IT says make <subject> insignificant.
"There are gardeners now. They came to the garden in vessels of bronze and they move through the groves in rivers of thought"
The gardeners here being the Vex mind. The vessels of bronze are their metal bodies.
"This is the vision I had when I leapt from the shores of time and let myself sink."
To have this make sense, Pujari dies when she leaps from the shores of time. This will make sense later on.
"I walked beneath the blossoms. The light came from ahead and the shadows of the flowers were words. They said things but I will not write them here.
At the end of the path grew a flower in the shape of a ghost. I reached out to pluck it and it cut me with a thorn. I bled and the blood was light"
Confirming that the setting is the black garden.
"The ghost said to me: you are a dead thing made by a dead power in the shape of the dead. All you will ever do is kill. You do not belong here. This is a place of life.
The traveler is life, I said. You are a creature of the darkness. You seek to deceive me."
But I looked behind me, down the log slope where the blossoms tumbled in the warm wind and the great trees wept sap like blood or wine, and I felt doubt."
When my ghost raised me from the sea there was a thorn-cut in my left hand and it has not healed since"
Okay, now for the explanation.
Pujari died when she leapt from the shores of time. She drowned. This is why her ghost raised her from the sea.
This confirms <subject> is in the black garden, since the legend mentions trees having sap of blood, which is in the riddle.
The event which cut Pujari is in the dream, which is in the riddle.
The flower would not be looked down by the dreaming God, but The thorn that grows on to Would. Hence, the answer.
But I lost anyways, so who cares.