Eldritch Gatling Gun (5e Optimized Character Build)
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The warlock gets in his fighting stance, ready to take on the minotaur in front of him. It growls and stomps on the ground with its foot. The warlock, his eyes steely, raises his shield and sword, ready for the attack. Suddenly, the minotaur charges directly at the warlock. The warlock's eyes narrow, and he glares at him. Suddenly, four bolts of crackling energy shoot from the warlock, blasting the minotaur backward against the wall, and it collapses.
This build is designed to shoot eldritch blasts like its nobody's business and deal maximum possible damage with them.
This build is a fun one, as you don't need to be high level to do a lot of damage with it, and it scales very well. The idea is to be an eldritch blaster, able to do lots of damage to individual targets very quickly without expending spell slots. It works best on individual targets, but it can work on groups as well.
The build is very simple. All you need to do is take at least two levels of Hexblade Warlock and at least three levels of Sorcerer (the subclass doesn't matter). Take the Eldritch Blast cantrip, and when you get to 2nd level of Warlock, take the Agonizing Blast eldritch invocation. This allows you to add your Charisma modifier to your Eldritch Blast. Next, take three levels of sorcerer, which gets you Metamagic. Take the quickened spell option, which allows you to cast a spell as a bonus action. At this point, you are a 5th level caster total, so your Eldritch Blast goes up to two beams.
This is another, similar build that you can take to achieve the same goal. Either start with Variant Human or Custom Lineage as your race, and take Eldritch Adept as your feat. Then, use Eldritch Adept to take the Agonizing Blast eldritch invocation. Start with one level in Warlock so you can get Eldritch Blast, and then take at least 4 levels of Sorcerer. This gives you an Ability Score Increase to increase your Charisma score even further, as well as an increase to your maximum number of sorcery points and another 2nd-level spell slot. This does require you to take Variant Human or Custom Lineage, but, in the end, it is a much more efficient build.
The Build Past 5th Level
If you decide to keep the build going after 5th level, then there are several options you can do. If you take the main build, with two levels of Warlock and three in Sorcerer, then it is recommended that you level up Warlock from here to get 2nd-level spell slots and Pact Boons. If you take the alternative build, you should increase your Sorcerer level to get 3rd-level spells, then your Warlock to get more spell slots and Eldritch Invocations. Either way, it doesn't really matter what you take after 5th level, as the core of the build is complete by that point. Just do whatever you want to, and have fun!
When you get into combat against a singular creature, use your Hexblade's Curse to curse a target as a bonus action, which allows you to add your proficiency bonus to damage rolls against the target and score a critical hit on a 19 or 20, and then just cast Eldritch Blast (two beams at 1d10 + charisma modifier + proficiency bonus, which should at this point be at least 1d10 + 4 + 3 (if you took a race that got a bonus to your Charisma score and rolled for stats), so 1d10+7 damage for each blast). Next round, if your target is still alive, use Eldritch Blast and then Quickened Spell to cast it as a bonus action again, so you deal 4d10 + 28 (an average of 52) force damage against one target.
When you get into combat against multiple, weaker creatures, don't bother with the Hexblade's Curse- it's just another bonus action you're missing out on. Instead, convert spell slots into more sorcery points, and then keep on blasting forever! Yee-haw! Just remember, the maximum amount of sorcery points you can have at any time is equal to your sorcerer level.
This build is based around the Sorlock build, which is Sorcerer + Warlock, one of the most versatile and powerful builds in the game. You can do several other Sorlock builds in addition to this, including the 1200-foot Spell Sniper, the Coffeelock, and the Sorlockadin. My point being, it's a very versatile build, and you can do a lot of other fun optimized builds in tandem to this one. So, do whatever you want! And remember, the point of D&D is to have fun, so if your build is irritating other people or your DM, then maybe you should rein it in a bit. However, if it doesn't, then go crazy!