The Blood of Dawnwalker: How to Unlock Blood Surge in Svartrau City

Blood Surge is a Vampirism ability in The Blood of Dawnwalker that makes an enemy explode, damaging everything nearby. Bosses take straight damage instead of popping. It is gated behind Vrakhir blood, and the earliest reliable way to get that blood is a small detour inside Svartrau City rather than a boss fight.

Quick answer: Get the Treasury Key from the ledger in the Greifberg Cathedral belltower room, unlock the Treasury building in the cathedral garden, loot the Phial of Xanthe’s Blood from the chest on the second floor, then drink it from your inventory to make Blood Surge available in the Vampirism tree.

What Blood Surge does and what it costs

Blood Surge is a night-only active ability with a 30 second cooldown. Firing it costs 3 Activation Charges plus 25 percent of Coen’s current health, so it is a burst tool rather than something you spam. The explosion scales with the ability’s level, and it has four levels total.

Level	Area damage / radius	Upgrade cost
1	178 in 3m	1 Skill Point, Vrakhir Blood required
2	222 in 4m	1 Skill Point, 1 hour, 10 Corruption
3	267 in 5m	2 Skill Points, 1 hour, 12 Corruption
4	311 in 6m	3 Skill Points, 2 hours, 14 Corruption

Note: unlocking the ability is only half the job. Like every skill in the game, you still have to be at a built road shrine to spend the Skill Point that actually learns it and raises its level.

Two ways to get Xanthe’s blood

The ability requires you to drink Xanthe’s blood, and there are two routes to that. You can defeat Xanthe and drain her rather than simply killing her, which also opens the option to invite her into your mind. Or you can skip the fight entirely and take the Phial of Xanthe’s Blood that sits in the Cathedral Complex Treasury.

The phial route is the one worth doing early. It costs a little time and one Time Segment, but it leaves your options with Xanthe herself completely intact, including sparing her later during The Cycle of Love.

Getting into the cathedral in Svartrau City

Open your map and head for Greifberg Cathedral in Svartrau City. Daytime is far simpler here, because the main doors are open and you can walk straight in. Your first entry triggers a cutscene with Father Florin.

Coen walking up to the cathedral doors in Svartrau City with quest objectives in the corner — Approaching Greifberg Cathedral during the day, when the main doors are unlocked. Image: Rebel Wolves

At night the complex is locked down. Your way in is the southeastern tower, using Shadowstep and the wooden platforms to keep your stamina topped up until you reach the roof, then dropping inside. Xanthe is in the cathedral at night giving orders to her followers, and being spotted starts her boss fight early, so stay out of her sight if you are not ready for that.

Treasury Key location: the belltower ledger

Inside the cathedral, find the Acolyte standing guard by the belltower door. Her name is Abelone, and she will not let you past on her own.

Talk to her and pick the “Maybe I could help you?” dialogue option. Helping with her task consumes 1 Time Segment and unlocks the door behind her.

Quest tracker visible as Coen moves down a cathedral corridor toward the guarded door — Moving through the cathedral interior toward the belltower door. Image: Rebel Wolves

Go into the room and look at the table. There is a chest worth looting, but the item you need is the Treasury Ledger sitting on the table.

Inspect the ledger properly rather than just picking it up. Examining the cover reveals a key tucked inside it, and you walk away with the Treasury Key.

Inspecting the open Treasury Ledger on the table, with a Skip prompt on screen — Inspecting the Treasury Ledger reveals the Treasury Key hidden in the cover. Image: Rebel Wolves

Phial of Xanthe’s Blood location in the Treasury

Leave the cathedral interior and head out into the garden. The Treasury is the locked building close by, in the northern part of the complex.

Coen running through Svartrau City toward the locked Treasury building — Crossing the cathedral grounds to reach the locked Treasury. Image: Rebel Wolves

Use the Treasury Key on the door. If the prompt does not appear, you are at the wrong building, since the key only works on the Treasury itself.

Go up to the second floor and look for the small golden chest. Opening it gives you the Phial of Xanthe’s Blood.

The chest on the Treasury's upper floor holding the Phial of Xanthe's Blood — The golden chest on the Treasury’s second floor holds the Phial of Xanthe’s Blood. Image: Rebel Wolves

Drink the phial and confirm Blood Surge unlocked

Open your inventory and consume the Phial of Xanthe’s Blood. Do not leave it sitting in your bag, because the phial does nothing until you drink it.

You know it worked when the CORRUPTION RISES prompt appears alongside a “New Vampiric Powers Available” notification, with Blood Surge named. From there, visit a road shrine and spend a Skill Point on Blood Surge in the Vampirism tree to actually learn it, then slot it into one of your four night-time Active Ability quick slots.

Two things commonly stop people short. Vampirism abilities are night-only, so Blood Surge will not fire during the day no matter how many charges you have. And Vampirism entries stay greyed out until your Corruption is high enough, which you raise by feeding on animals and people with Voracious Bite, humans being the faster option.

Grabbing the phial early is the cleaner play. Xanthe is the first boyar most players run into, and walking into that fight with an exploding finisher already slotted is a real advantage. Just as importantly, taking the blood from the Treasury leaves every conversation with Xanthe still on the table, including the option to spare her, which clears Greifberg Castle of supernatural enemies before the run at Brencis.