The Fool

Unlike other warlocks who have acquired their power through making a pact with a powerful entity, you take power from whoever's foolish enough to give it to you.  You might be an ex-cultist that has taken his knowledge of soul-stealing to make a name for himself, or a merchant that has discovered he can do so much more with his ability to persuade.

A Great Pitch

You gain proficiency in persuasion.  If you already have proficiency, you may choose from these skills instead:

• sleight of hand
• arcana
• insight
• perception
• deception
• performance

You can also give yourself advantage on a persuasion check once per long rest.

Soul Contract

You can attempt to convince a creature to sign their soul away for a payment of your choice.  The victim must make a wisdom saving throw against your spellcasting dc; on a success, it will reject your offer.  on a fail, it will accept your offer.  If the victim accepts your offer, you either gain Soul Points equal to the creature's CR or level, or you can learn a spell that the victim knows, if any.  Soul Points can be used to give yourself spell slots akin to the Sorcerer, with 1 Soul Point = 1 Level.  You have a total of Soul Points equal to your warlock level that regenerate on a long rest, however you can have as many Soul Points as you can get in between long rests.  You can remember a number of spells from your victims equal to your warlock level/2 (rounding up).

Bargaining

If a victim makes a successful saving throw against your Soul Contract, you can increase your payment in order to make the victim roll again with disadvantage.  If the victim rolls a nat 1 on its initial saving throw against your Soul Contract, you can use this ability to double your profits from the contract.  This ability can be used once per long rest.

Underling

If a victim signs your Soul Contract, you can command the victim to accomplish a task for you that takes less than 1 hour.  The victim will give up on the task if a loss of hit points brings it to below half of its hit point maximum.  This ability can be used once per long rest.

Fine Print

You can add clauses to your Soul Contract that give the following benefits:

• You don't require a payment
• You obtain both Soul Points and a spell if the victim knows one.
• The Soul Points gained are doubled compared to a standard Soul Contract.
• The spell is permanently added to your spells known, at no cost to your current spell list.  Yes, this includes lvl9 spells, though you'll need to have enough soul points to make a slot for it if you want to use it.

This ability can be used once per long rest.