Level 100 Exsanguinate Ascendant^3.21

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 and Corrupting Fever later. You can start as early as mid-Act 2 - although I advise to check the performance of both skills if possible. 
The safe moment would be to start near the end of Act 3 - the level scaling of Exsanguinate should outscale your weapon damage by now.

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.
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 DoT side of Exsanguinate.

Gearing early:
Even though we would ideally run Armour/Evasion gear, it is better and easier to start with 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.
From now on try to find 3-link gear with RGG colours (Splitting Steel - Onslaught Support - Chance to Bleed Support)
After opening the Submerged Passage take Steelskin and Frostblink from Tarkleigh. If you can, buy War Banner from Nessa.
After killing Brutus (The Caged Brute), take either Flame Dash or any Added Damage support (to help with the damage early on - assuming you have the links)
If you didn't take Flame Dash, buy it anyway.
If you can afford it, buy Efficacy Support (for future use with Exsanguinate)  Vitality and Clarity (if you're struggling with mana) from Nessa.
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)

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:

You can start using it right away, although it won't add much damage as of now. You want to link it with Efficacy Support.
After killing The Weaver (Sharp and Cruel) take Cruelty Support from Silk.
If you can afford it, buy Controlled Destruction Support from Yeena. At this point you could start using Exsanguinate, if you have the correct sockets (RRBB - Exsanguinate - Controlled Destruction Support - Cruelty Support - Efficacy Support - 3-link will suffice).
Complete the Deal with the Bandits quest, killing all bandits and claiming two skill points from Greust.
Remember to complete The Way Forward quest and to collect your skill point from Bestel (Lioneye's Watch - Act 1)

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 (spinning blades)
The Chamber of Sins Level 2 (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.
If able, buy either Malevolence (if you need more damage) or Purity of Elements (if you want to have an easier time leveling with resistances and ailments).
Note that we are not using Purity of Elements in maps - it is a leveling convenience. If you choose to take Purity of Elements for now, also buy Malevolence and level it while playing.
You may also want to buy Pride and start using it after taking the Sovereignty aura wheel on the tree.
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 (if you are fine with attributes, take Lapis Amulet for the extra Intelligence).
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 isn't needed for us, so we can skip it.



ACT IV:

After using Deshret's Banner (Breaking the Seal) take Summon Stone Golem.
Complete the Labirynth after claiming the waypoint in Crystal Veins.
After killing Malachai and the Beast (The Eternal Nightmare) you may take Chain Support to help with clearing if you need it or Arcanist Brand as a mean to trigger our curse.
You may now buy Brutality Support if you have sockets to fit it (RRRBB or RRGBB - for Brutality or Chain).

You should definitely use Exsanguinate by now.

GEM OVERVIEW (gems are listed in the order of importance):

DAMAGE SKILL: Exsanguinate - Controlled Destruction Support - Brutality Support - Cruelty Support - Efficacy Support (RBRRB)
AURAS: War Banner - Vitality - Malevolence/Purity of Elements - Pride (RRBR) (note that you may not be able to use all of them after taking the Sovereignty wheel - at the moment it is important to have a higher level Vitality for the sake of consistency)
CURSE: Vulnerability - Arcanist Brand (RB)
REST OF THE SKILLS: Flame Dash - Whirling Blades (if you're using a Rune Dagger) - Summon Stone Golem (RGB)

With this gem setup you will probably go to the end of acts, especially at leaguestart scenario.


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

Other quests are completed automatically while progressing through the Act - you may skip the Niko questline for now.



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 Granite Flask.
After killing High Templar Avarius (Death to Purity) take Crimson Jewel (we want %life, %global phys, %inc Dot, %DoT Multi, %Physical DoT Multi)

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

Other quests:
You may kill Utula (The King's Feast), if you do, take Assassin's Haste jewel.



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. Buy Determination and start leveling it.
You can start using three 50% Auras when Sovereignty, Leadership and Charisma wheels are allocated.

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