Path of the Dieselforged
Warforged Barbarians who wish to pursue the Path of the Dieselforged augment themselves with an engine that works off of Arcane Diesel, a byproduct created by the presence of their own lifeforce. Since Warforged don’t have adrenaline in quite the same way as races of flesh and blood, they use the engine a power boost in moments of dire need. Arcane Diesel is not necessarily the most efficient fuel, but it is abundant to the Dieselforged.
1st Level Rage Alternative: Diesel Rage.
The Arcane Diesel engine replaces the barbarian’s rage. Instead of having a defined number of rages that you can use, you have Diesel Points equal to 10 times the number of rages that you would otherwise be able to use. You regain half of these upon completing a short rest and all of them upon completing a long rest. At level 20, you do not gain infinite diesel points. Instead, you retain the same amount of diesel points, but regain 1 at the start of each turn, or 1 every 6 seconds out of initiative. You enter your rage as a bonus action for 1 diesel point.
The benefits of being in a Diesel Rage include: You gain your rage bonus equal to a barbarian’s normal rage bonus to the damage of melee attacks using strength. You are resistant to slashing, piercing, and bludgeoning damage. You have advantage on strength checks and saves.
3rd Level: Overheat
Whenever you spend a Diesel Point, you gain 2 heat points. At the start of your turn, you lose a number of heat points up to your proficiency bonus with a minimum of 2 (subject to environmental temperature). You have a heat threshold equal to double your level. If you have a greater amount of heat points than your heat threshold, you take fire damage equal to the number of heat points minus your heat threshold at the end of your turn. For example, if you are level 2, and have 5 heat points after the start of your turn, you would take 1 fire damage, as you have 5 heat points and a heat threshold of 4.
When you have heat, your melee attacks are considered magical and deal an additional amount of fire damage equal to one quarter of the amount of heat points you have (rounded up). If someone touches you directly, without adequate thermal protection, as defined by the DM, they take this amount of fire damage as well.
When you take fire damage, and are below your heat threshold, you may reduce that damage by an amount of your choosing, after resistances. However, for each point that you reduce the damage, you gain a heat point. Be wary, as this can cause you to go above your heat threshold if you reduce the damage by too large of an amount, which may prove exceedingly dangerous.
When you take cold damage, and have heat, you may reduce that damage, and lose that many heat points. If you reduce your heat to zero, have not reduced the cold damage to zero, and are in a rage, you may choose to end your rage in order to take no cold damage whatsoever until the start of your turn. If you do, and wish to enter a rage again in the next minute, you must use both your action and bonus action to do so.
When you are in extreme heat, the rate at which heat decays is reduced by one (minimum 1) but you are otherwise unaffected by it. When you are affected by extreme cold, the rate at which your heat decays is increased by 1. If you are unable to decay heat at the start of your turn, it requires both your action and bonus action to enter a rage. Otherwise, you are unaffected by extreme cold.
3rd Level: Custom Parts
You may customize your body to better synergies with your Diesel engine. You may pick two of the following features, and another at 6th, 10th and 15th level. When you level up, you may swap one feature for one other, so long as you meet its requirements. For these features, any DC you have is equal to 8+con+proficiency:
Chain Whip/Tow Hook: 3 Diesel Points.
As a bonus action or reaction when an opponent leaves your range, once per round, if you have a free hand, you may make an attack or a grapple with an integrated chain that you are proficient with, which has 10 feet of reach. As an attack, this has an additional +5 to hit. As a grapple check, this gets a +5 to its modifier. It deals 1d8 bludgeoning when used as an attack. Also, when grappled with the chain, the target takes fire damage from your heat. This chain stays deployed, able to be used as a weapon or to grapple, without the +5 bonus, until your rage ends or you use your object interaction to retract it. You must use this ability again to make a reaction grapple, but using it to make attacks is free.
Expel Hot Oil (Requires Level 6): 4-10 Diesel Points.
As a bonus action you spend an amount of diesel points, no greater than half your level, rounded up. Instead of gaining heat from these diesel points being spent, you lose 2 heat points for each diesel point spent. You spit scalding oil out in either a 15 foot cone or a 5×30 foot line at a high pressure. All within the area must make a Dexterity saving throw or take fire damage equal to 1d4 for each diesel point expended, or half on a successful save. If you spend 10 points to use this ability, and use it as a 15 foot cone, any targets hit within 5 feet of you have disadvantage on the save, and if they have an ability that allows them to take zero damage on a successful save, such as evasion or shield master, it has no effect.
Increased Torque: 2-20 Diesel Points.
As part of any roll relating to strength, be it a weapon attack, strength check, or strength save, you may spend an even number of Diesel points no greater than your level. For every 2 you spend, you add +1 to the modifier of the roll. For checks and saves, you may add this after you know whether the roll succeeds or fails, and for attacks, the modifier applies both to the attack and damage roll, but must be decided before the roll is made.
Roll Coal (requires level 15): 20 Diesel Points
You gain an additional action to take on your turn. This ability requires no action economy but can be used only once per turn. You also cast a non-magical version of Stinking Cloud centered on yourself as part of using this ability, requiring no components or concentration. People within 10 feet of you are considered deafened and silenced until the start of your next turn, as the sound of the engine roaring drowns out all sound. You treat the heavy obscurement from Stinking Cloud as light obscurement, as it is hard to blind yourself with your own exhaust. (The fact that you do not need to make a save versus the other effect goes without saying, as Warforged don’t need to breathe.)
Shocking Alternator: 2 Diesel Points per charge
When you enter or maintain your Diesel Rage, you may choose to spend 2 additional Diesel Points to develop an electric charge. This charge lasts for the duration of your rage, and may stack a number of times equal to your level. The next time that you hit someone with a metal weapon, someone hits you with a metal weapon, or if you make direct physical contact with someone or their metal armor, you deal 1d6 lightning damage to them for each charge. Upon dealing damage, all charges are expended.
6th Level: My Own Mechanic
Dieselforged, after their self-augmentation, become adept at repairing themselves. You may make medicine checks on yourself (and other Warforged you happen to find) without use of a healer’s kit, and in 5 minutes, or as part of a short rest, you may make one such check. You heal for an amount equal to the amount rolled, and if the check was a 15 or higher, you may remove one status effect, ability score reduction, or a level of exhaustion from yourself or the target. You are considered proficient for these medicine checks if you are not already proficient. You may only do this once on the same target until they take a long rest.
10th Level: Diesel Accoutrements
You gain a series of benefits related to various accessories you have integrated into yourself. Pick 2 of the following abilities. You may swap these out when you level up, and gain a third one at level 14.
Air brake: you can not be moved against your will while your feet touch the ground.
Analog System: your free will may not be affected by any means while in a Diesel Rage, and as a reaction to being targeted by such an effect, you may enter a Diesel Rage.
Chains: you are unaffected by difficult terrain, and are unable to slip on slippery ground. You gain climbing speed equal to your movement speed. While in a Diesel Rage, your movement speed can’t be reduced below half.
Overbuilt: You are treated as a huge creature for the purposes of carrying capacity, push drag and lift capacity, and grappling.
Radiator: while above your heat threshold, you may reduce your heat points again at the end of your turn by an amount equal to your proficiency bonus. If you reduce your heat in this way, creatures within 5 feet of you take fire damage equal to the number of heat points you lost.
14th Level: Improved Temperature Control.
You are resistant to fire and cold damage, including overheat damage. You may now choose whether or not you are affected by extreme heat or cold if you are in an extreme environment. Fire damage you deal ignores resistance and treats immunity as resistance (this does not stack with itself). While at 0 hit points, damage caused by Overheating will not cause you to take a failed death save.