Clan Steelheart

Clan Steelheart is generally regarded as the most powerful clan in a martial sense. They are the hardiest clan of all, made up of warriors and miners. They, between the great Displacement and the war of Reclamation held the only mountain inhabited by dwarves, Last Peak, and therefore held the most honor in a traditional sense. amongst other dwarves. However, they are often regarded as gruff or rough around the edges when interacting with other dwarves, and can often have a hard time making agreements with the other clans.
Clan Steelheart is lead by a rather young, yet skilled Jarl, Jarl Gunndar Giantfeller. Gunndar was given his name for killing several giants, either through outsmarting them, or out preforming them in combat. Jarl Gunndar was given Last Peak from his father, and has held it against frost giant and white dragon attacks, even when they were one after another. He held claim to the title of King due to command of the last mountain held by any dwarf, and his ability in combat as a leader, and a fighter. However, the title of king was given to another Jarl, with most clans sighting Clan's Steelheart's quickness to battle, fearing that it could lead the dwarves down a path of perpetual war. 
Clan Steelheart holds Last Peak, formerly known as Steelmount. A large, hot, city among the snowy, northern mountain peaks. It's known for it's massive mine, probably the largest mine known in the world. It's forges burn bright with molten lava and it has the only forge hot enough to smelt Adamant. The city's wealther and more affluent live towards the top of the inner mountain while the lower class live closer to the mines. It not only provides a buffer from the dangers of the mine to the more powerful, but also puts the lower class closer to work. Most young men are still expected to serve time in the mine, at least a year, as a rite of passage, even if they are children of the Jarl.
Clan Steelheart currently faces a threat to the North. Giants and a new breed of Tall dwarves have attacked their scouting parties. They have called most of their troops back home to deal with this threat and get ready for all out war.
Clan Steelheart has the slayer, a type of barbarian which takes a grudge upon certain type of monster or humanoid which has wronged them or their ancestors. When a Barbarian picks the path of slayer they gain:

• Slayer's Grudge. At level three you pick a type of of monster, dragons, giants, or two types of humanoids as the targets of your grudge. Whenever you are raging your bonus rage damage against said type of creature is doubled, you gain resistance to any damage dealt by the targets of your grudge while raging, and you gain advantage on survival checks to track the targets of your grudge, and nature checks to recall information upon them. You can choose an additional Slayers Grudge at level ten
• Slayer's Speed. At level six you can dash as a bonus action provided you are moving towards a hostile creature. You and your group can move at double speed when traveling overland, provided you are not attacked during the day, and moving with intent to kill a target of one of one of your Slayer's Grudges.
• Slayer's heart. Starting at level ten, you have advantage on saving throws caused by effects from targets of your Slayer's Grudge, and attacks by hostile creatures against targets other than you have disadvantage while you are within five feet of that creature.
• Slayer's destruction. At level fourteen you can take the attack action as a bonus aslong as your attacks are against a target of your slayer's grudge.

Clan Steelheart also counts as a subrace

If you are a member of Clan Steelheart, you gain:

• Ability Score Increase. Your strength score increases by 1.
• Dwarven Toughness. You gain an addition one hitpoint per level.
• Iron Fist. Your unarmed strike damage is increased to 1d4 as opposed to 1. If you gain a 1d4 unarmed strike from another source this increases to 1d6, but no higher.

Culture

Shared customary codes and values

• Fight or Die There is no flight, just fight. If someone is threatening your holds or the lands of your people you need to hold it, don't surrender what's yours when you can stand and fight.
• Work Hard The clan cannot move forward if most are not working. Pick up a pickaxe and get to mining, no wealth is made without sweat, blood, or both.
• Dominance We are the strongest clan, therefore we should rule all clans. Martial ability is key over all else, that's why we are the only clan that holds a mountain while all others are driven to the foothills, forests, or swamps nearby. Our Jarl should be King of all dwarves.
• Settle the Score Any of those who have wronged us as a clan should suffer, no matter how long it takes for them to pay, they will, with blood. This goes doubly so for those who have taken our mountains, the Dragons and Giants.

Common Taboos

• Fleeing Battle Die with glory and honor, there's no worth to living as a coward. If you abandon your brothers in battle, don't come back to the clan.
• Creative pursuits A tool or weapon is only worthwhile in function, form is worthless, this makes gems and gold linings worthless to put on or into armor and weapons.
• Diplomacy with Monsters We'll never make friends with the savage beasts which threaten our lands and have slaughtered our people. An orc is no friend and never will be, and making nice with a dragon or giant is a capital offense.