Online:Scion of the Blood Matron

Quick Walkthrough
# Speak to Rahaja outside the crypt or seek out a priest to cure your infection.
# Enter the crypt.
# Learn about Mother Lamae.
# Submit yourself to the blood matron.
# Prey upon 10 worm cultists.
# Speak to Lamae Bal.

Detailed Walkthrough
You must have contracted Vampirism before you can begin this quest. Vampirism may be spread through special groups of bloodfiends that spawn at night time in certain places, or you may acquire it through a vampire player who has the Blood Ritual skill unlocked and has not given the gift to anyone else in the last week.

If you were bitten by another player (which can only happen at an altar in your faction's final zone), a scroll will appear before you immediately afterward, directing you into the crypt under the altar. 
If you are bitten at Hircine's altar by another player, you will instead read the scroll on the altar. It states:

: 
: 
:Initiate, a child of Mother Lamae has bestowed a gift upon you. They are the Bloodspeaker. They have chosen you to undergo the ancient rite of the Blood Matron. This is a great honor.
: 
:To be a child of the Blood Matron is to forsake the Divines. If you are ready to join us, step through the portal. Otherwise, return to your city and speak to a cursed Priest of Arkay. The Blood Matron will not induct the unworthy or weak.
: '''

Inside the crypt, you will find Rahaja, who will instruct you on how to become a full vampire. The next sections only apply if you were bitten by a bloodfiend; if not, skip ahead to when you enter the Blood Matron's Crypt.

If you were bitten by a bloodfiend, you need to speak to Vorundil in Rawl'kha (Reaper's March), Evermore (Bangkorai), or Riften (The Rift), depending on your alliance. 
:"Ah, that look. So familiar. Your mouth is dry, your blood boils in your veins, while your skin turns as cold as ice. Your body does not accept the blessing for what it is. It resists."
:What is happening to me?
:"You were attacked by a vampire, were you not? The blood of Mother Lamae flows within you. I wonder: will you embrace it, or will you fight it?"
:'''I don't know how to do either.
:"If you wish to reject it, a wretched priest of Arkay will gladly take your coin to do so. Otherwise, listen to the blood that pulses through you. Let it guide you to Rahaja. She will show you the way to Mother Lamae's embrace."
:Thank you.
:"Follow your blood. It will lead you to Rahaja. Perhaps we will be kin one day."

At this point, the quest begins. You can choose to ask him about Mother Lamae.
:Who is Mother Lamae?
:"Mother Lamae was the first of us. Molag Bal made her his unwilling bride and through her brought terror to the night. Through her, he created the vampire kin. She is the blood-matron, mother to us all."''

You can choose to speak to a priest and heal yourself, or talk to Rahaja and embrace the full power of the vampire. 

Arkay's Cure
To cure yourself, speak to Prelate Sabinus in the Mages Guild in the main city of your faction's final area. He does want you to make a donation to the temple in exchange for the cure, which you can refuse to pay.
:"May Arkay drive back the darkness, forever more."
:I was attacked by a vampire. I fear I may become one of them.
:''"Those wretched creatures slink in the darkness, cowering from the light of Arkay. Fear not, with Arkay's grace I can purify you. All I ask is a simple donation to the temple."
::Here is an offering. Please begin. [  gold]
:::"Blessings upon you, child. Now, let Arkay's light burn the curse from your blood."
::I won't pay for your cure.
:::"That is unfortunate. May Arkay's light shine upon you."

Embracing the Blood
When you get close to a Vampire Ritual Site, you will see a cloud of red mist coming toward you. In front of your eyes, it transforms into Rahaja.
:"We had hoped you would come. We have watched you ever since you first emerged from Coldharbour. If you were like other mortals you would soon turn. But you are unique."
:How am I unique?
:"The Dark Father, Molag Bal, has corrupted you. Only Mother Lamae herself may turn you into one of us. Kneel before this monument, and pray she welcomes you into her embrace."''

Activate the monument not far from Rahaja. It transports you into the Blood Matron's Crypt. Talk to Rahaja again inside.
:"Our kind live in darkness and feed on life. Walking among us requires forsaking the gods and embracing the blessing of Mother Lamae. Will you proceed?"
:I will.
:"First, you must experience the history of our kin, through our mother, Lamae Bal. How she was first defiled, then forsaken."
:How do I do that?
:"There are two basins, the basin of suffering and the basin of loss. First, you must drink the basin of suffering, and witness how our mother suffered at the hands of Molag Bal. Then you must show your hatred for Molag Bal by profaning his symbol."
:What about the other cup?
:''"After you've profaned Molag Bal's symbol, you will drink from the basin of loss and see how Lamae Bal was forsaken in her time of suffering. Then you will profane the symbol of the Foresaker."
:Who is the Foresaker?
:"That is not for me to reveal. Now, drink the cup of suffering. Profane the symbol of Molag Bal, the Defiler. When you have drunk from both cups, you will kneel in the pool and present yourself to Mother Lamae."''

Mother of Vampires
Lamae's Suffering
thumb|left|Lamae's Suffering
The basin of suffering is to the right and north of Rahaja and the center pool. You drink some of the water and see a vision with Lyrezi, Selenu and Vraseth - the progenitors of their respective vampire bloodlines.
: 
:Lamae Bal: "When I was a priestess of Arkay, Molag Bal ravaged me and left me for dead. A group of nomads tried to purify me with fire. But I awoke... changed."
:Vraseth: "Elder, what do you believe happened to her?"
:Selenu: "Her body was…mangled, rent apart by a terrible darkness. Its corruption is still on her. I can feel it."
:Vraseth: "Is it true her bones healed on their own?"
:Selenu: "Yes. That is why I insisted we perform this rite at once."
:Lyrezi: "Elder! The girl!"
:Selenu: "No, we are too late.
:No! back away!"

Lyrezi will walk towards the fire, promptly before being drained by Lamae. Selenu is drained after, while Vraseth runs away, ending the vision.

Head to the southern pillar where blue flames burn on top of a symbol of Molag Bal's face. 
:Lamae Bal: "Molag Bal, Father of Torment, we curse you! You sought to poison us with your blood. But we survived. And from your poison, we grew. King of Corruption, your children are coming. They will defile and destroy you."

As you perform the ritual, the symbol begins to tremble. The candles fall off, and eventually, the whole thing collapses into a heap of stones on the ground.

Lamae's Loss
thumb|right|Lamae's Loss
In the other northern corner of the room is the basin of loss. Drinking from it reveals another vision.
:Lamae Bal: "Arkay! Answer me! I am your priestess! Answer! Molag Bal said you would not come. He said you turned your light away from me. Arkay! Do you hear me? You are false! I reject you!"

This time, Lamae Bal wanders alone among the flames in the aftermath of her transformation.

Across from Molag Bal's destroyed symbol is the symbol of Arkay. 
:Lamae Bal: "Arkay the Forsaker, we curse you! You left us to suffer in darkness. But we survived. And in darkness we grew. Now, we feed upon your followers. We will use their stolen strength to conquer and consume you."

The Power of the Blood Matron
thumb|right|The blood transfusion
—With both symbols destroyed, enter the pool of black waters. The strange female voice commands you to feed, and four vampires begin to drain your blood. From your blood, a woman clothed in white and red—the blood matron herself-appears. She tells you to kill ten Worm Cultists and to revel in your new powers.

Note that at this point, your first two abilities in your bar and your ultimate ability will be replaced by Drain Essence, Mist Form, and Bat Swarm, respectively, and weapon swapping is not possible until the end of the quest.

Enter the tunnels through the northern door, then follow the northwestern path and drop down into the water. The worm cultists are level 42. You do not have to kill them with a vampiric ability; you can use your regular weapon to do that.

Return to the pool, and speak to Lamae Bal when all are dead. 
:"My beautiful abomination, how you shine in the dark. Now listen. I must warn you."
:Speak, and I will listen.
:"Relish this new life I have given you. Feed and grow powerful. Find others of our kind. Form families. Bring new children into the fold!"

Notes
Despite the quest stages calling the Blood Scion ultimate a Vampire Lord, Blood Scions are in fact not Vampire Lords, but are simply a type of mimicry as confirmed by Leamon Tuttle (49:32-50:35)  on ESO Live.
 

Quest Stages