Level 93 Vaal Reap Ascendant^3.23

Notes

LEVELING GUIDE:

We're starting as a Splitting Steel Scion, using Physical Damage, so we wouldn't need to respec tree later (and also because Splitting Steel is a really solid Act 1 skill).
We're switching to Exsanguinate at level 12.
Low Life version switches to Low Life after campaign

IMPORTANT LEAGUESTART GEARING INFO:

Weapons for Splitting Steel:
The best weapons will be two-handed Axes, followed by two-handed Swords - it is important to use two-handed weapons, as the base damage is far greater than the one-handed versions.
If able, use the recipe:
Melee Weapon + Magic/Rare Rustic Sash + Blacksmith's Whetstone = Magic Melee Weapon with "Heavy" (Magic Belt) or "Serrated" (Rare Belt) prefix

Weapons for Exsanguinate:
At the beginning of the game look for +1 to Level of All Physical Spell Skill Gems on Wands/Sceptres/Rune Daggers/Shields. It will be the easiest to get at the very start (ilvl2 requirement for the mod).
If you won't get it, use the recipe:
Caster Weapon + Magic/Rare Chain Belt + Blacksmith's Whetstone = Magic Caster Weapon with "Apprentice's" (magic Belt) or "Adept's" (rare Belt) prefix
We can choose between Wands, Sceptres and Rune Daggers (two of a kind or with a Shield). Wands give us the best implicit, but they come with the highest Intelligence requirement, so it would be easier to go to Sceptres or Rune Daggers later. 
Ideally we would run low-base Wands while leveling.
Mods on caster weapons such as "Adds # to # Fire Damage to Spells" can help us in the short time, but won't scale us further, as we will lean towards a physical DoT side of Exsanguinate.

Gearing early:
Even though we would ideally run Armour/Evasion gear, it is better and easier to start with Armour or Armour/Energy Shield bases. 
Change to Armour/Evasion bases once you have enough chromes and jewellers to get the right socket colours (which would probably be in early maps).


ACT I:

After beating Hillock (Enemy at the Gate) take Splitting Steel from Tarkleigh.
After delivering Medicine Chest (Mercy Mission) take Chance to Bleed Support and Quicksilver Flask from Nessa. You want to link Splitting Steel with Chance to Bleed Support (GR)
After opening the Submerged Passage (Breaking Some Eggs) take Frostblink from Tarkleigh. If you can, buy War Banner and Steelskin from Nessa.
After killing Brutus (The Caged Brute), take Flame Dash and replace Frostblink with it. If you can, buy Enduring Cry, Vitality and Efficacy Support (Efficacy for the future use with Exsanguinate) from Nessa.
If you need damage and have 3-link, you can buy Added Fire/Cold/Lightning Damage Support, based on your links.
You can also start buying Lifetap Supports to change Mana Cost of skills to Life Cost of skills, which will be easier to sustain.
After entering The Cavern of Wrath (The Siren's Cadence), take Exsanguinate from Nessa and switch to it - we will now use Exsanguinate - Efficacy Support (RB).
From now on you want to link all your skills except for Auras and Exsanguinate with Lifetap Supports - this will simplify our playstyle, as we can completely ignore mana regeneration issues. Details in the 'Skills' section in PoB.
You may struggle with Intelligence early on - you can solve it by buying Lapis Amulet from Nessa.

Skill/respec points:
Book of Skill (one passive point) - The Dweller of the Deep
Book of Skill - The Marooned Mariner
Book of Skill - The Way Forward (keep in mind you will complete this quest in Act 2, and then you need to come back to Lioneye's Watch to claim the reward from Bestel).

Trials of Ascendancy:
Lower Prison (spike traps)

Other quests:
A Dirty Job (optional - grants Book of Regrets (two Respec Points))


ACT II:

It doesn't really matter which gem you'll take from Greust after completing Intruders in Black - none of them is relevant to us.
However, after the Intruders in Black quest you will be able to buy Herald of Purity from Yeena. Buy it if you can.
Remember to complete The Way Forward quest and to collect your skill point from Bestel (Lioneye's Watch - Act 1)
After killing The Weaver (Sharp and Cruel) take Cruelty Support from Silk.
If you can afford it AND you already have a proper 4-link, buy Controlled Destruction Support from Yeena. 
At this point you'd have these sockets: RRB(B) - Exsanguinate - Cruelty Support - Efficacy Support - (Controlled Destruction Support)
Complete Deal with the Bandits quest by killing all bandits (Oak, Alira and Kraityn) and claim two skill points from Eramir.

Skill/respec points:
Eramir's Favour (two Skill Points received automatically while talking with Eramir) - Deal with the Bandits
Book of Regrets - Through Sacred Ground

Trial of Ascendancy:
The Crypt Level 1 (hovering sawblades)
The Chamber of Sins Level 2 (floor sawblades)

Other quests:
You will encounter Einhar and get a quest with introduction - you can ignore it for now.
The questline The Great White Beast - Through Sacred Ground is optional.


ACT III:

After fighting Piety (Lost in Love) take Vulnerability from Maramoa. As mentioned in the Act 1 section, ideally you'd want this to be linked with Lifetap Support to simplify mana issues and reservation values.
If able, buy Pride from Clarissa. You want to switch Herald of Purity for Pride. We won't be able to reserve both until a bit later.
After meeting with Lady Dialla (The Gemling Queen/The Ribbon Spool/Fiery Dust questline) take the amulet based on the attribute you have issues with (most likely Lapis Amulet for the extra Intelligence or Jade Amulet for extra Dexterity).
After killing General Gravicius (Sever the Right Hand), there isn't any required gem to get as a reward.

Skills/respec points:
Book of Skill - Victario's Secrets
Book of Skill - Piety's Pets

Trial of Ascendancy:
The Crematorium (furnace traps)
The Catacombs (blade sentries)
The Imperial Gardens (dart traps)

Other quests:
A Swig of Hope can grant you rare Ring - it is probably too tedious to complete though.
A Fixture of Fate - we have to do it, so that we can earn Arrogance Support from Siosa.


ACT IV:

After using Deshret's Banner (Breaking the Seal) take Summon Stone Golem. It will help us with Life Regeneration, so that we will be able to use our skills more freely. We will be dropping it later, but it is helpful at that stage.
Complete the Normal Labirynth after claiming the waypoint in Crystal Veins.
After killing Malachai and the Beast (The Eternal Nightmare), take Chain Support (improving clear with Exsanguinate).
If you can, buy Arcanist Brand and link it to Vulnerability to automate the curse.
You may now buy Brutality Support if you have sockets to fit it.

Now your Exsanguinate links should look like this:

MAIN: Exsanguinate - Efficacy Support - Cruelty Support - Controlled Destruction Support - (Brutality Support) - (Chain Support) (RBRB(RG)) 
(you will likely have a 4-link at this point, so Brutality and Chain are in brackets as an upgrade when you get 5- and 6-link)


Skill/respec points:
Book of Skill - An Indomitable Spirit


ACT V:

After slaying Overseer Krow (Return to Oriath) take a rare Ring from Lani - prioritise the base that will help with your lowest Resistance.
After killing Justicar Casticus (The Key to Freedom) take either Jade Flask or Granite Flask - both will be amazing for defenses.
After killing High Templar Avarius (Death to Purity) take Crimson Jewel (we want %life, %global phys, %inc Dot, %DoT Multi, %Physical DoT Multi - there is a high chance this jewel would be useless for us)

Skill/respec points:
Book of Skill - In Service of Science
Book of Skill - Kitava's Torments

Other quests:
Killing Utula (The King's Feast) grants a rare weapon - neither of them interests us.


ACT VI:

After clearing Twilight Strand (Fallen from Grace), take the Book of Regrets from Lilly Roth. She will sell you all the available gems. 
From her you can buy Arrogance Support, which you will link with Vitality, so that it is reserved on your Life instead of your Mana.
You should be able to reserve War Banner, Herald of Purity, Pride and one other 50% Aura (you can choose between Determination (armour), Grace (evasion) and Malevolence (more damage and skill effect duration)).

GEM OVERVIEW:

MAIN: Exsanguinate - Efficacy Support - Cruelty Support - Controlled Destruction Support - (Brutality Support) - (Chain Support) (RBRB(RG))
MANA AURAS: War Banner - Herald of Purity - Pride - Determination/Grace/Malevolence
LIFE AURAS: Vitality - Arrogance
CURSE: Vulnerability - Arcanist Brand - Lifetap Support
MOVEMENT/UTILITY: Flame Dash - Steelskin - Enduring Cry - Lifetap Support
OTHERS: Summon Stone Golem

From now on complete the quests and trials, collect points, receive rewards, complete Labirynths.


LABYRINTH/ASCENDANCY ORDER:

Normal Labyrinth (Level ~33, start of Act 4): 'Strength and Intelligence', and 'Passive Point', leading to the Templar.
Cruel Labyrinth (Level ~55, start of Act 8): 'Hierophant' and 'Passive Point', leading to Path of the Templar.
Merciless Labyrinth (Level ~67, end of Act 10): 'Path of the Templar' and 'Strength and Dexterity', leading to the Duelist.
Uber Lab (Level ~75, yellow maps): 'Passive Point' and 'Gladiator'.


PANTHEON:

Major: Soul of the Brine King (Stun "Immunity" and Freeze Immunity)
Minor: choose based on the content you're doing.


SWITCH TO LOWLIFE:

The guide is set up to transition the character to Low Life at the end of the campaign. We will then start reserving Petrified Blood to patch up the Life loss from reservation - see the proper 'Skills' set. 
Keep in mind - although it is a big chunk of damage thanks to Pain Attunement, it is also a decrease in survivability. You can stay with previous auras and not go Low Life if you prefer.
There is a version of tree/skills/gear, designed to lean to survivability. You can go that way if you prefer.


EXSANGUINATE VS REAP:

The guide suggests using both Exsanguinate and Reap at the endgame. The idea is to use Exsanguinate and Chain Support for clear and Reap with Swift Affliction for bosses. 
In theory Reap does less damage than Exsanguinate with three stages, but in practice Reap feels much better in boss fights, because you have to press it once, and both spells have long cast time.
While leveling I'd advise to stick with Exsanguinate - it should be enough damage, and it is available earlier (Exsanguinate is available from level 12, Reap - from level 28).
Specific gem links are in the 'Skills' section of the PoB.