Found the Incantations of Iriolarthas at the body of the demilich.

Two Levels because :
1 Level for entering Iriolarthas Lair, and
1 Level for Defeating Iriolarthas himself.
This is the Spoiler free Explanation, for further Information ask the Player.

1x Potion of Greater Healing (found)

1 Level for defeating Auriel.

Used Bag of Beans with 8 Beans: 86, 66, 32, 5, 41, 81, 68, 79
2x Egg Nests. Each with 4 Eggs. Made all 8 Con saves (Pala Aura +5 and Flash of Genius in Group)
CHA 8 -> CHA 12 , STR 8 -> STR 12

Found Avarice' Spellbook at her dead body along with her Staff of Frost.

Found Yilsebek's Spellbook at the dead drow body.
1x Potion of Surperior Healing (found)

Made a deal with 3 night hags and forgot the name of his familiar.
Ate a purple pear and gained Charm of Sending.

Drank random potion and learnt Minor Illusion cantrip.

Indefinite Madness: You don't like how people always judge you.

1x Spell Scroll of 'Fireball' (found)
Gave the Cauldron of Plenty to the speaker Danneth Waylen, who offers each character a common magic item of their choice from Xanathar’s Guide to Everything - though he still needs 48 hours to acquire them. Magical armor obtained in this way is limited to leather, scale, or chainmail.

• STR +2 -> INT +2
• Light Armor -> Brewers Supplies
• Medium Armor -> Alchemist's Supplies
• Battle Axe -> Cartographer's Tools
• Handaxe -> Land vehicles
• Light Hammer -> Navigator's Tools
• Warhammer -> Water vehicles

Bought:
Snowshoes: -2 GP
Crampons: -2 GP
Shield: -10 GP

Got cursed for opening the grave. Removed curse by drinking blessed water from Statue of Silvanus (Greater Restoration).
Bought:
Familiar Ingredients: -10 GP

1x Potion of Invisibility (found)
Found Astrix' spellbook at her frozen corpse.
Spent 150 GP to copy spells: Shield, Comprehend Languages, Detect Magic

Found Nass Lantomir's spellbook at a frozen corpse.
Spent 150 GP and copied spells: Counterspell

Found the Incantations of Iriolarthas at the body of the demilich.

Two Levels because :
1 Level for entering Iriolarthas Lair, and
1 Level for Defeating Iriolarthas himself.
This is the Spoiler free Explanation, for further Information ask the Player.

1x Potion of Greater Healing (found)

1 Level for defeating Auriel.

Used Bag of Beans with 8 Beans: 86, 66, 32, 5, 41, 81, 68, 79
2x Egg Nests. Each with 4 Eggs. Made all 8 Con saves (Pala Aura +5 and Flash of Genius in Group)
CHA 8 -> CHA 12 , STR 8 -> STR 12

Found Avarice' Spellbook at her dead body along with her Staff of Frost.

Found Yilsebek's Spellbook at the dead drow body.
1x Potion of Surperior Healing (found)

Made a deal with 3 night hags and forgot the name of his familiar.
Ate a purple pear and gained Charm of Sending.

Drank random potion and learnt Minor Illusion cantrip.

Indefinite Madness: You don't like how people always judge you.

1x Spell Scroll of 'Fireball' (found)
Gave the Cauldron of Plenty to the speaker Danneth Waylen, who offers each character a common magic item of their choice from Xanathar’s Guide to Everything - though he still needs 48 hours to acquire them. Magical armor obtained in this way is limited to leather, scale, or chainmail.

• STR +2 -> INT +2
• Light Armor -> Brewers Supplies
• Medium Armor -> Alchemist's Supplies
• Battle Axe -> Cartographer's Tools
• Handaxe -> Land vehicles
• Light Hammer -> Navigator's Tools
• Warhammer -> Water vehicles

Bought:
Snowshoes: -2 GP
Crampons: -2 GP
Shield: -10 GP

Got cursed for opening the grave. Removed curse by drinking blessed water from Statue of Silvanus (Greater Restoration).
Bought:
Familiar Ingredients: -10 GP

1x Potion of Invisibility (found)
Found Astrix' spellbook at her frozen corpse.
Spent 150 GP to copy spells: Shield, Comprehend Languages, Detect Magic

Found Nass Lantomir's spellbook at a frozen corpse.
Spent 150 GP and copied spells: Counterspell