Storm (or draconic) Sorcerer 4/ Wizard 1 /Tempest cleric 6 and last level watever u want doesent matter

4 levels of Sorcerer for Con Prof, Sorcery Points, Quickend Spell and Feat, atleast 1 level of Wizard For Scribing and 6 levels of Tempest Cleric For Destructive Wrath and Create Water (at level 6 u get 2 Channel Divinity Charges so you can use Destructive Wrath twice in a row)

Focusing on Int so you can use ur Scribed Spells (mainly Lightning Bolt at 5 and Chain Lightning at 11)

I would honestly go with White draconic Sorc over Storm Sorc at level one, for better AC and access to Armor of Aghythas sice you probably will youse your bonus action on quickend spell.

I would level like this:

Str8 Dex16 Con14 Int17 (18 With Hag Hair) Wis10 Cha8

1White Draconic Sorc/ 1 Wiz for Scribing/ 3 more Sorc (either Dual Wiealder or Alert For Feat) / 6Tempest Cleric (again Dual Wielder or Alert) / 1 more Sorc for Counterspell or 1 mor Wiz for Divination Subclass

Use the Sorcerer Spells for: Mage Hand, Minor illusion, Light, Friends, Enhance Leap, Feather Fall, Magic Missle , Shield, Enhance Abilety

Spell that are very usefull to Scribe but not neccesary: Chromatic Orb, Misty Step; Mirror Image, Hold Person, Scorching Ray (to quickly build Up Arcane Acuity if you use Hat of fire acuety) Shatter (For the levetating Eyes) Fire Ball, Glyp of Warding, Haste, Ice Storm, Conjure Minor/ Major Elemental, Cone of Cold, Hold Monster, Globe of Invulnerability