Emissaries are as varied as the patrons they serve, a Fiend may spitefully send you to punish a fellow warlock who displeased them, an Archfey may have you gathering people to worship them, or a Celestial could have you out collecting buttons.  No matter the request you know better than to argue, the same tie that allows you to jump between planes allows your patron to pull you directly to them should they become displeased. 

Expanded Spell List

The Emissary 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.

Emissary Expanded Spell

1st	bane, command
2nd	spiritual weapon, blindness/deafness
3rd	blink, slow
4th	resilient sphere, confusion
5th	contagion, wall of force

Imposing Presence

When you pick this subclass your patron gives you the knowledge necessary to carry out their will.

You gain proficiency in medium armor, heavy armor and martial weapons.  You also gain proficiency in either Persuasion or Intimidation. 

Fighting Style

At 1st level you adopt a particular style of fighting as your specialty. Choose one of the following options. You can’t take a Fighting Style option more than once, even if you later get to choose again.

Defense

While you are wearing armor, you gain a +1 bonus to AC.

Dueling

When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.

Great Weapon Fighting

When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

Protection

When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.

Two-Weapon Fighting

When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.

Planar Conduit

When you become an Emissary at level 1 your ties with your patron are deepened. 

Once per day you may call upon your patron and gain advantage on skill checks for one skill of your choice for the next ten minutes.  However, deeper ties with your chosen patron mean that they have greater control over you.  If the actions you take during this time would run counter to your patrons nature your patron may attempt to wrest control of your body from you.  If this happens make a charisma saving throw (DC 15), on a successful save you maintain advantage for the remainder of the time, on a failed save your patron takes control of your mind and body for one minute before you manage to regain control and the connection ends. 

You may also use this link to voluntarily allow your patron to speak through you.

Rift Assault

Starting at level 6 your otherworldly ties allow you to manipulate rifts to attack as well as evade.

When you make a melee weapon attack, you can teleport up to 10 feet before each attack to an unoccupied space you can see. 

If you hit at least two different creatures with the action, you can make one additional attack with it against any creature

You also gain the ability to detect and know the destination of recent points of teleportation.

Rift Amplification

At level 10 as you continue to travel between planes of existence you learn how to absorb energy from the rifts to augment your attacks.

Whenever you teleport roll a d6 and add it to the weapon damage of your next attack.  The number of dice used is doubled for each consecutive teleport on your turn.

1st teleport 1d6, 2nd teleport 2d6, 3rd teleport 4d6, 4th teleport 8d6.

At level 14 this die is increased to a d8 and at level 18 increased to a d10.

Diplomatic Immunity

Starting at level 14 those who would impede the will of your patron are to be punished. 

When another creature hits you with an attack you may use your reaction to teleport them before your patron to answer for their crimes. 

At the end of the targets next turn it returns to the space it previously occupied, or the nearest unoccupied space.  The target takes 10d6 psychic damage and is frightened of you.

You must finish a long rest before you can use this feature again.