Tempest Widow

Based off Arcane Trickster, but focusing on Lightning Damage and Crowd Control.

Level 3: Spellcasting

You have learned to cast spells.

Cantrips. You know three cantrips: Mage Hand and two other cantrips of your choice from the Wizard spell list.

Whenever you gain a Rogue level, you can replace one of your cantrips, except Mage Hand, with another Wizard cantrip of your choice.

When you reach Rogue level 10, you learn another Wizard cantrip of your choice.

Spell Slots. The Tempest Widow Spellcasting table shows how many spell slots you have to cast your level 1+ spells. You regain all expended spell slots when you finish a Long Rest.

Prepared Spells of Level 1+. You prepare the list of level 1+ spells that are available for you to cast with this feature. To start, choose three level 1 Wizard spells.

The number of spells on your list increases as you gain Rogue levels, as shown in the Prepared Spells column of the Tempest Widow Spellcasting table. Whenever that number increases, choose additional Wizard spells until the number of spells on your list matches the number in the Tempest Widow Spellcasting table. The chosen spells must be of a level for which you have spell slots. For example, if you’re a level 7 Rogue, your list of prepared spells can include five Wizard spells of level 1 or 2 in any combination.

Changing Your Prepared Spells. Whenever you gain a Rogue level, you can replace one spell on your list with another Wizard spell for which you have spell slots.

Spellcasting Ability. Intelligence is your spellcasting ability for your Wizard spells.

Spellcasting Focus. You can use an Arcane Focus as a Spellcasting Focus for your Wizard spells.

Level 3: Static Cling

When you deal sneak attack damage, you can choose the damage to be lightning instead of its normal damage type, when you do so, all further instances of sneak attack are lightning damage. This resets each instance of combat.

Level 9: Marking Jolt

When you deal sneak attack damage, you can cause the creature to become marked, when an ally within 30ft of you attacks the marked creature, you can use your reaction to make a ranged weapon attack and deal 3d6 lightning damage, this damage increases at levels 11 (4d6), 13 (5d6), and 19 (6d6)

Level 13: Mesmerizing Storm

You can cast these spells: suggestion, charm person or command without expending a spell slot, the dc for these matches your 10+IntMod+Proficiency Bonus. You may only cast one spell this way once per long rest.

As well, you may cast web at 9th level, to which your DC is the same as your spell DC. When a creature starts it's turn in the web, it takes 8d6 lightning damage.

Level 17: Arcwielder's Brand

When you hit a creature with your sneak attack and mark it, it automatically fails on the next save that it makes.