Becoming a lich

Before you start

• Becoming a lich comes from Skyrim - Undeath SSE 1.7, with Undeath Classical Lichdom, its Hardcore Mode, Phylactery Limits and Prelude to Purgatory v3 beta on top. All of them are in base GTS.
• You need to be level 30 for the first quest to start. To make the lich's items you need 50 Enchanting and 75 Conjuration, and gear that raises them counts. To cast the ritual spell you need more than 100 Health, and you can't be a vampire. No perk is needed.
• Three choices on the way shut you out for good, because each takes away the only source of something the ritual needs. Don't cover Vyngald's grave again in Exhuming Power: take his shroud. In Arkay the Enemy, kill the captive priest and take his heart instead of setting him free. In Infernal Alchemy, don't tip the cauldron over or fail five mixes.
• It can't be undone. Nothing in GTS takes the lich's powers away once the ritual is done.

The quests, in order

1. In their Footsteps: once you reach level 30, a Torn Page from Traveler's Diary lies in the Silver-Blood Inn in Markarth. Read it. It sends you to a wrecked Vigil of Stendarr caravan in the Reach, where Ambush Orders lead you to Ravenscorn Spire in Eastmarch and the two volumes of Antioch's Journal.
2. That starts three quests, which you can do in any order. In Exhuming Power, near Winterhold, kill the necromancers at Vyngald's grave and take the Shroud of Vyngald from his coffin. His ghost attacks.
3. In Arkay the Enemy, at the Temple of Arkay in Falkreath Hold, kill the captive priest and take the Priest of Arkay's Heart. You need it later to open the way to the Black Book.
4. In Infernal Alchemy, on a plateau above the Reach, kill the four necromancers and use their cauldron. Your mix decides the lich you become. Nightshade, a human heart and Bloodroot make Embalming Essence, for a lich that keeps its flesh. Namira's Rot, a skull and Deathbell make Namira's Corrosion, for a skeleton.
5. Once all three are done, Scourg Barrow starts. The necromancers carry a book that can take you to Scourg Barrow in the Dragontail Mountains and back. Put the priest's heart in the brazier there to open the secret door, and defeat Antioch.
6. Whispers of the Veil: read the Black Book in Scourg Barrow. It takes you into Apocrypha. Use the forbidden book there to get the Ritual Notes, which start The Path of Transcendence.
7. A courier then brings you a message from The Broker. It opens The Broker's Shack in western Falkreath Hold and marks it on your map.

What you make for the ritual

Everything is made at a necromantic altar. There is one in The Broker's Shack. Ravenscorn Spire and the Solitude Sewers each get one once you buy that place's notes from the Broker.

• The Phylactery: a Solution of Magicka Concentrate (3 Nirnroot, 5 Moon Sugar and a Potion of Muffling), an Ensorcelled Vessel (a Flawless Amethyst, 3 Vampire Dust, an empty black soul gem and Purified Void Salts), and a Crushed Black Pearl.
• Purified Void Salts are 5 Void Salts, a filled black soul gem and another Crushed Black Pearl, so you need two Black Pearls in all. The Broker always has one in stock. The oysters and clams Undeath adds can give one too, but not often.
• In GTS the Potion of Muffling is a potion that muffles your steps, from a mod that renamed it. Besides the Broker, there are some at Septimus Signus's Outpost, in the College's Hall of Acumen, and in Dawnguard's Inner Sanctum and Boneyard.
• The Elixir of Defilation: a Deadly Poison, Nightshade Extract (8 Nightshade), a Poison Bloom, Finely Ground Bone Meal (10 Bone Meal), and the essence or corrosion from the cauldron. The Broker doesn't sell Poison Bloom in GTS. One lies in The Broker's Shack, the necromancer Selonius carries one, and Arcadia in Whiterun stocks it.
• A ritual site. Buy the notes for Ravenscorn Spire's laboratory (1,750 gold) or the ritual chamber in the Solitude Sewers (1,000 gold). The sewers join the Winking Skeever, Castle Dour and the Bards College.
• The Shroud of Vyngald, plain or dyed at the altar with the Broker's dyes, sets the lich's colour: black, green or white. The ritual uses it up.
• The recipes stop showing once the ritual is done.

The ritual

The Ritual Notes give the same order. Get it wrong and the ritual kills you, so save first.

1. Go to your ritual site and place the Phylactery on its pedestal by the circle.
2. Carry the Shroud of Vyngald.
3. Stand in the circle and cast Unbind Soul, which the Ritual Notes taught you. It's a master Conjuration spell for both hands that costs 450 Magicka, and you need more than 100 Health to cast it.
4. Drink the Elixir of Defilation within 60 seconds. Drunk without Unbind Soul, it deals 100 damage a second. If you are a vampire the spell won't cast, but the Elixir is still lost.
5. Keep standing in the circle. After a few seconds the ritual begins, and it holds you up while it works. When it ends you see "You have attained lichdom!"

What you get

• Two forms. The lesser power Assume Lich Form turns you into the lich, and Revert Form brings back your old look as a disguise. You wait 30 seconds before you can change back.
• In lich form you can't fast travel and your stamina empties. Unless you have the Masquerade perk, everyone attacks you on sight. You get Lich Conduit, Death Grip and Ice Coffin.
• In both forms: Necrotic Rejuvenation, which heals undead, plus Poison Shroud, Sacrifice Thrall, Lich Sight and Seed of Pestilence. You resist frost by 50% and are immune to poison and disease, but fire hurts you twice as much. You can breathe underwater, and in lich form you can walk on water and move faster.
• Your Health no longer regenerates: you lose 100 Health and gain 100 Magicka. You take a quarter less damage, except from silver. As a lich you take no fall damage. Wear the Ring of Mirrors (Mortal) to hide the undead look.
• Food, ingredients, healing potions and healing spells never work on you again. Other potions work at half strength for an instant. The Hardcore Mode in GTS is what makes this hold even after the Transcendence perk.
• A tooltip says Necrotic Resilience makes you 25% more resistant to physical damage. In the files that's only its description: the real cut is the quarter less damage above.

Dying, and the phylactery

• As a lich you can't die normally. When you would, your body reforms at your phylactery's site, fully healed. If you die in your mortal form, all your gear comes off.
• In a plane of Oblivion, during parts of Waking Nightmare, and in parts of The Forgotten City, you see "You can't reach your phylactery from this location" and you die for real.

Getting stronger

• Prelude to Purgatory replaces Undeath's soul feeding. Kill things as a lich to raise the Lichdom skill, up to level 14, with one perk each level. Open it with the Tween Menu key in lich form.
• There are 12 perks. Magicka Weave adds Magicka and its regeneration. Transcendence gives more experience, stops people hating your lich form, and lets your mortal form be a vampire. Flesh Transcendence changes your looks and gives Masquerade. The others are Hardened Weave, Mirror Weave, Supreme Weave, Frozen Cadavers, One Body, Join the March, Wraith Form, Dark Pact and Spirit of Midnight.
• The Ring of Mirrors is made at the altar from a filled black soul gem, Void Salts and a silver ring, once you have Flesh Transcendence. After you reform three times you get 10% more experience.

From base GTS 118's own files: the records as the game uses them, the mods' own settings files as Jay's collection ships them, and GTS's own menu setup. Each line was read by one reader and checked by a second. A line marked Setting is a menu or settings-file option: what it says is the default. Your own add-ons can change any of this.