The Red Knight

 You seek the truths of the universe that you might master them.  There is no greater truth to the mortal plane than the omnipresence of war and conquest.

You form a Pact with the Red Knight, the Lady of Strategy herself, and gain the benefit of her keen battle prowess in exchange for being her representative in the affairs of man.

Time to put the "war" in "Warlock."  Become the Red Bishop.

Castling

At 1st level, you gain the Castling ability.  When active, your Arcane Focus takes on the form of a Common non-magical melee martial weapon of your choice.  Higher rarities become available at higher levels.  You may use your WIS modifiers instead of STR for Hit/DC and Damage.  Your weapon continues to function as an Arcane Focus and maintains any magical properties it held, but you lose the ability to use ranged magic from your personal spell table.  Any spells with a range of SELF or TOUCH are still accessible.  This weapon cannot be used as the Pact Weapon for Pact of the Blade, but may be dual-wielded with the usual disadvantages [with permission of the DM].

In addition, your AC score increases by 1 and you gain advantage on Wisdom throws.

This ability lasts until dismissed, then is unavailable until after a Short Rest.

At level 6, your staff may become an Uncommon non-magical melee martial weapon of your choice.

At level 11, your staff may become a Rare non-magical melee martial weapon of your choice.

At level 16, your staff may become a Very Rare non-magical melee martial weapon of your choice.

En Passant

When an enemy comes within or leaves a 5 ft. radius of you, you may use your Reaction to make a melee attack against them.  You may only do this upon approach or exit, not both.  Alternatively, when the enemy comes within 5 ft., you may instead choose to trigger your Castling state.

In addition, when an enemy comes within 5 ft. of you, they must succeed in a Dexterity saving throw against DC10 + your Wisdom modifier.  If they fail, they gain disadvantage on any attack that requires physical movement so long as they are visible to you and within 5 ft.

Battle Prowess

Beginning at level 10, you gain the ability to read the battlefield when in your Castling state.  Any attack against you that you can see must succeed in a Dexterity saving throw against DC10 + your Wisdom modifier.  If they fail, the attack gains disadvantage.

Warlord's Focus

Starting at level 14, while in your Castling state, you gain uncanny focus, granting you immunity to status effects that target the mind (Charm, Stun, Fear, Exhaustion).  Additionally, any spells you cast that require Concentration will remain until either they or Castling are dismissed, as your focus is unbreakable.

You may now use your ranged magic up to half of its usual range.