Thunderblade

Thunderblades seek to embody lightning, striking with immense force and wielding the power of angry skies against their foes. It is said that the most powerful among their order have eyes the colour of lightning, and speak with the force of a thunderstorm.

Blitzkrieg

You have advantage on Initiative rolls. In the first round of any given combat, your weapon attacks score a critical hit on a roll of 19-20.

Shock and Awe

Starting at 7th level, you can cast Misty Step without expending a spell slot. 
Instead of being surrounded by mist, a bolt of lightning descends from above and strikes you; you vanish in the blast, reappearing at your target location in another lightning strike. Creatures within 5 ft. of you after you teleport must succeed a DC 14 Constitution saving throw, taking 2d6 Lightning damage on a failed throw and half as much on a success.
You can make one weapon attack immediately after resolving the lightning damage from your teleportation.

After casting Misty step in this way, you cannot cast it again until you take a long rest.

Lightning Infusion

At 10th level, you can infuse up to two weapons over the course of an hour-long ritual. Weapons infused in this way are enwreathed in electricity, dealing an additional 1d6 Lightning damage whenever you strike with them. This additional die is not multiplied when rolling a critical hit.
The electricity calms and fades away when your weapons are stowed or sheathed, flaring violently back into existence whenever the weapon is drawn with intent to harm.

Overwhelming Force

Starting at 15th level, you roll one additional die when landing a critical hit. Additionally, in the first round of any given combat, your weapon attacks score a critical hit on a roll of 18-20; otherwise you score a critical hit on a roll of 19-20.

Pact of the Storm

At 18th level, you strike a primordial accord with elemental electricity and embody it in all aspects.

• You can now cast Misty Step as outlined in the Shock and Awe class feature at will, no longer restricted to casting it once per long rest. The save DC for creatures near your teleportation destination is now 18, and damage is increased to 4d6
• Your damage bonus from the Lightning Infusion class feature becomes a d8 instead of a d6.
• Your walking speed increases by another 10 feet.
• Your very touch is electrified; you can now cast Shocking Grasp, dealing an additional 1d8 Lightning damage when you connect with it (total 5d8).