A Warlock of The Fiend

The Fiend Patron

You have made a pact with a fiend from the lower planes of existence, a being whose aims are evil, even if you strive against those aims. Such beings desire the corruption or destruction of all things, ultimately including you. Fiends powerful enough to forge a pact include demon lords such as Demogorgon, Orcus, Fraz’Urb-luu, and Baphomet; archdevils such as Asmodeus, Dispater, Mephistopheles, and Belial; pit fiends and balors that are especially mighty; and ultroloths and other lords of the yugoloths.

Expanded Spell List

The Fiend 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	Burning Hands, Command
2nd	Blindness/Deafness, Scorching Ray
3rd	Fireball, Stinking Cloud
4th	Fire Shield, Wall of Fire
5th	Flame Strike, Hallow

1st-level Spells

Burning Hands is a decent AOE (Area of Effect), especially at low levels, and since warlocks get armour and more HP than other arcane spellcasters like the wizard you can survive being close enough to melee to use it. However, I wouldn’t use it beyond very low levels. You’ll get more total damage out of Hex or other spell options despite Burning Hands’ scaling. Command is a great control/debuff effect and scales really well with your spell slots.

2nd-level Spells

Blindness/Deafness is a powerful debuff, but allowing repeated saves can make it unreliable. Scorching Ray is a bit redundant with Eldritch Blast, but it scales very well and benefits from the same tactics.

3rd-level Spells

A good AOE blast and a good area control effect. Fireball remains the best instantaneous AOE damage spell at every spell level until around spell level 8, and while the Warlock can’t cast Fireball past 5th level, it still remains a perfect go-to AOE blast option. However, remember that you will often get better results out of spells with ongoing effects like Hunger of Hadar, and with so few spell slots you need to squeeze as much out of them as you can. Stinking Cloud is an ongoing AOE save-or-suck effect, but creatures within the area are Heavily Obscured so it’s hard to attack them. Hunger of Hadar is likely a better choice in most cases.

4th-level Spells

Fire Shield is fine for “gish” builds, but if you’re going for a warlock gish (A character that is skilled in both physical combat and the use of magic) you’re going to play a hexblade. Fire Shield also seems redundant with Armor of Agathys, which notably lasts longer, provides Temporary Hit Points, deals more damage to attackers, and scales with spell level. Wall of Fire is one of the best area control spells in the game and with the right invocations you can push and pull enemies through it to repeatedly capitalize on the guaranteed damage dealt when a creature passes through the wall.

5th-level Spells

Flame Strike is Fireball, but a smaller AOE and worse damage. Sure, some of the damage is radiant, but if damage resistance is a problem you should be using Eldritch Blast since nearly nothing can resist Eldritch Blast. Hallow is very situational.

Dark One's Blessing

Starting at 1st level, when you reduce a hostile creature to 0 hit points, you gain Temporary Hit Points equal to your Charisma modifier + your warlock level (minimum of 1).
This makes Fiendish Vigor considerably less important. It also makes it important that you occasionally pick off weak foes to ensure that your Temporary Hit Points are up before you focus on more important foes. So just remember the creature just needs to be hostile, so a permissive DM might allow you carry around a bag of angry rats and kill one whenever you need temporary hit points.

Dark One’s Own Luck

Starting at 6th level, you can call on your patron to alter fate in your favour. When you make an Ability check or a Saving Throw, you can use this feature to add a D10 to your roll. You can do so after seeing the initial roll but before any of the roll’s effects occur.
Once you use this feature, you can’t use it again until you finish a short or Long Rest.

Fiendish Resilience

Starting at 10th level, you can choose one damage type when you finish a Short or Long Rest. You gain Resistance to that damage type until you choose a different one with this feature. Damage from magical weapons or silver weapons ignores this resistance.
This doesn’t specify restrictions on the damage type, so if you want to do Slashing for a while then switch to Radiant, you can do it. This is one of very few ways to get resistance to Force damage, but you still want to use this for common damage types like fire, poison, and slashing.

Hurl Through Hell

Starting at 14th level, when you hit a creature with an attack, you can use this feature to instantly transport the target through the lower planes. The creature disappears and hurtles through a nightmare landscape.
At the end of your next turn, the target returns to the space it previously occupied, or the nearest unoccupied space. If the target is not a fiend, it takes 10D10 psychic damage as it reels from its horrific experience.
The creature is removed from the game until the end of your next turn, allowing to temporarily banish the creature, and potentially place hazards in and around its space such as Hunger of Hadar, Wall of Fire, or the rest of your party.
Once you use this feature, you can’t use it again until you finish a Long Rest.

Gaming by etsy

Warlock of The Fiend

Straightforward and effective, The Fiend offers mostly offensive options which improve the Warlock’s ability to kill stuff, but also offers some extremely potent defensive abilities. The Fiend is a blaster first and foremost, and is heavily dependent on fire damage, so consider taking the Elemental Adept feat.