Duskblade

The pact is made with a ring that fell to earth from the heavens near the wreckage of a crashed Spelljammer.  It allows you to create pact weapons.  The powers of the ring represent the shield and spell abilities for flavor purposes.  I am going for a Green Lantern style of ability usage with an emphasis on 80s and 90s themes.

Constantly hitting with the same weapon or Eldritch Blast over and over again can get stale.  To combat this I am going for thematic descriptions of the abilities.  The pact weapon could be a Indiana Jones’ Whip, Duncan McLeod’s Katana, Captain America’s Shield, Thor’s Hammer, etc.  Eldritch Blast can be represented as the Glaive from Krull, Cyclops’ beams of energy from his visor, Iron Man’s repulsors, or Street Fighter style slashing energy projections.

Arcane Channeling

As a bonus action, choose 1 creature you can see within 30 feet of you. The creature is the target of your power of will for 1 minute, until you die, until it dies, or until you become incapacitated; whichever comes first. While this ability is in effect, you gain the following abilities:
• You gain a bonus to damage rolls against the target equal to your proficiency bonus.
• Attack rolls against the target are critical hits on a 19 or 20.
• It the target dies, you regain hit points equal to your warlock level + your charisma modifier (minimum of + 1)
• You cannot use this feature again until you complete a short or long rest.

Eldritch Shield

As a reaction to hit by the target of Arcane Channeling, you may use Dusk Shield. On a 4+, the attack misses you, regardless of the roll.

Improved Arcane Channeling

When the target of Arcane Channeling dies, you may transfer the effects to a new target.

Power of Will

Starting at 6th level, when you make an ability check or a saving throw, you can use this feature to add a d10 to your roll. You can do so after seeing the initial roll but before any of the roll's effects occur.

Once you use this feature, you can't use it again until you finish a short or long rest.