The Magengineer

Instead of devoting yourself to a patron, you have devoted yourself to undiscovered magic the art of magitech.  Much like an artificer you are obsessed with technology. However, you believe technology is the key to evolution.  An evil Magengineer may want to enslave the world to machines or force people to become machines whereas a good Magengineer may want to light path to the future and coexist in world of machines and unforseen technology.

Expanded Spell List

The Magengineer 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.

Fiend Expanded Spells

Spell Level	Spells
1st	absorb elements, command
2nd	enhance ability, spiritual weapon
3rd	haste, protection from energy
4th	confusion, vitriolic sphere
5th	bigby's hand, mass cure wounds

Metallurgy

At 1st, you gain proficiency with Medium Armor, Heavy Armor, and Shields as well as proficiency with Smith Tools and two martial weapons of your choice. As long as you are wearing medium or heavy armor you gain a +1 bonus to AC and armor you are wearing becomes magical; your shield also becomes magical.

You also learn the Mending cantrip. It counts as a warlock cantrip for you but doesn’t count against your number of cantrips known.  If you later gain Pact of the Tome, Mending’s casting time is reduced to 1 Action.

Risk Factor

You have infused yourself with alien technology known as nanites. These nanites provide you with your magic as well as other unique abilities.
At 1st level, you may use your Charisma modifier in addition to your Dexterity on initiative checks.

As a Reaction to an incoming attack or an enemy casting spell, you may call upon the nanites, roll a d20 then refer to the following list:

1. • 1:  The nanites do nothing
   • 2:  The nanites turn you into a Homunculus as if using the spell Polymorph.
   • 3:  The nanites empowers ability to relay dangers you gain Advantage on all saving throws until your next turn.
   • 4:  The nanites cast Shield on you lasting until the start of your next turn.
   • 5:  The nanites heal you and six creatures of your choice that you can see and hear for 1d4 + your Charisma modifier.
   • 6:  The nanites cast Bane at will on you lasting for 1 minute.
   • 7:  The nanites play random musical tunes for the next hour that only you can hear.
   • 8:  The nanites stimulate your bodily function allowing you last twice as long in extreme weather conditions. This bonus lasts for 24 hours.
   • 9:  The nanites cast Shatter as a 3rd level spell centered on you.
   • 10: The nanites cast Thunderwave at will, centered on you.
   • 11: The nanites empower your attacks with overwhelming rage. You gain Advantage on all weapon attacks, but all incoming attacks have Advantage against you. These effects last for the next minute.
   • 12: The nanites whirl around you viciously all creatures within 10 feet of you including yourself take an amount of necrotic damage equal to your warlock level every round. This effect lasts for 1 minute.
   • 13: The nanites cast Hold Person on you using your spell save.
   • 14: The nanites zoom around you angrily, your physical body and voice change to what would be appropriate for the opposite sex. This change can only be reversed by Greater Restoration.
   • 15: The nanites cast Bless at will on you lasting for 1 minute.
   • 16: The nanites surround you with a draining aura. You take Disadvantage on all skill checks, ability checks, saving throws, attack rolls, and death saves for the next minute.
   • 17: The nanites expel green gas all creatures including yourself within 10 feet of you are affected by the spell Tasha’s Hideous Laughter.
   • 18: The nanites glow brightly for 1 minute during which you shed bright light in 20-foot radius and dim light for an additional 20 feet.
   • 19: The nanites heal you for 1d8 + warlock level.
   • 20: The nanites Reduce your size by half as if casting the spell Enlarge/Reduce. You must make a Constitution save equal to your saving throw.

    

You have 2 uses of this ability. You regain all uses after you finish a long rest.

Constructed Servants

At 6th level, you gain the ability to conjure a cohort of constructs.  Their combined CR cannot exceed 1 + 1/2 your warlock level (rounded down) and the total number of creatures you conjure cannot exceed your Charisma modifier. 

Summoning them requires a bonus action after which they last for 1 minute or until destroyed.  They act in initiative after you.  You must use a bonus action on each of your turns to direct them to attack otherwise they follow the last given command. They also get a bonus to attack and damage rolls equal to your Charisma modifier. Finally, they gain a number of temporary hit points equal to your warlock level divided by the number of creatures you conjured.

You can use this ability a number of times equal to 1/2 your Charisma modifier.
You regain all uses of this ability after a short or long rest.

Of Constructs and Magic

Starting at 10th level, the nanites flowing through your veins have changed your anatomy making you more like a machine.

You gain proficiency in Intelligence saving throws if you do not already and resistance to Psychic damage.
You can no longer be affected by curses and curse spell or effects.
You have advantage against the frightened condition.
Additionally, your construct cohort's weapons and natural weapon attacks are considered magical. They also gain a bonus on all saving throws equal to your Charisma modifier if they can see or hear you.

Magitech Lord

At 14th level, you have mastered the art of magitech. 

When you get this feature you may choose either Lord of War, Lord of the Forge, OR Lord of Machines.

Lord of War:  If you have the Pact of Blade, your pact weapon deals an additional 2d6 force damage on hit and you can never be disarmed.   Otherwise you start combat with a number of temporary hit points equal to 3 x 1/2 your warlock level. 

Lord of the Forge: Any Medium Armor and Heavy Armor you wear grants you +1 AC, +2 spell attack, and +2 DC as well as advantage against magical spells and effects. Also any medium or heavy armor you wear doesn't impede your movement.

Lord of Machines:  When you use your Constructed Servants feature your constructs' combined CR cannot exceed 1 + 2/3 your warlock (rounded down) instead of 1 + 1/2 your warlock level. Upon summoning them they gain a number of temporary hit points equal to your twice warlock level divided by the number of creatures you conjured instead of the normal amount.