You have made a pact with an Ancient Trickster. Whether they trick for the sake of chaos, to fulfil and aim or just for fun, they  love to play games with unsuspecting victims. Whether good or evil, the patron can be a powerful God, captivating Fey or  desirous Fiend. Notable examples in fiction and lore are Loki, Sheogorath, the Cthaeh and Crowley. 

Expanded Spell List (Ancient Trickster)

The Ancient Trickster lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you. 

Deft Fingers

Starting at 1st level, you gain proficiency with thieves tools. 

Duplicate

Starting at 1st level, you can use your bond with your patron to create an illusory duplicate of yourself.

As an action, you create a perfect illusion of yourself that lasts for 1 minute, or until your illusion is attacked and destroyed.

The illusion appears in an unoccupied space that you can see within 30 feet of you. As a bonus action on your turn, you can move the illusion up to 30 feet to a space you can see, but it must remain within 120 feet of you. For the duration, you can cast spells as though you were in the illusion's space, but you must use your own senses. Additionally, when both you and your illusion are within 5 feet of a creature that can see the illusion, you have advantage on attack rolls against that creature, given how distracting the illusion is to the target.

A creature may attack your illusion, and if it hits, the illusion is automatically dispelled. If the illusion is in the area of effect for a spell, even if it allows for a saving throw to take no damage, the illusion is destroyed; unless the spell deals only psychic damage. If a creature destroys the illusion with a melee attack, they take 2d6 psychic damage.

The armor class of your illusion is equal to 8 + your proficiency bonus + your charisma modifier.

You can use this feature a number of times equal to your proficiency bonus and recover all uses on a long rest. 

Trickster's Trade

Starting at 6th level, as a reaction to you or your duplicate being targeted by an attack, you may teleport into your duplicates space and the duplicate teleports into yours. The target of the attack then switches. When you use this feature you gain temporary hit points equal to your Warlock level.

You may use this feature only once per duplicate. 

It's a Distraction!

Starting at 10th level, if your duplicate is within 5ft of an enemy when a saving throw is made against one of your spells, it does so with disadvantage. 

Slippery Customer

Starting at 14th level, when you are concentrating on a spell, ranged attacks against you have disadvantage.