Hound

Hound is a melee focused specialist, a choice for rogues who pursuit survivability in heads-on fighting. It's main feature Adaptability enables Hound to ignore weapon property restriction on Sneak Attack, meaning any melee weapon can be used.

As still a rogue, Hound's main combat style is a hit-and-run. However, when situation doesn't allow any room to maneuver, Hound has ability to buy times until more martially focused party member can back up, or fight face-to-face and beat the crap out of an enemy who underestimates him. Adaptability feature enables 5th level Hound to make a melee weapon attack as Cunning Action as long as you didn't use Sneak Attack in that turn, making it possible to take Dodge action and still make an attack.

Hound should be built around Dexterity and Strength. The starting stat is optimized at 16 Strength and 14 Dexterity, or 14 Strength and 16 Dexterity, depending on your play style.

Hound has relatively high chance of hit thanks to the Adaptability feature that adds half of Dexterity Modifier to any melee weapon attack that lacks Finesse property. Though you must take caution since the bonus only extends to attack rolls, not damage rolls.

Some possible feat options for Hound are:

• Heavily Armored, if your party got a really good suit of a plate armor but no one uses it.
• Great Weapon Master, if you can get a proficiency in Heavy Two-handed weapons.
• Tough or Resilient, if you want to increase the survivability.
• Dwarf Fortitude, since dodge can be used very often.
• Sentinel, as you are often close to both enemy and friend.

Hound is a great option for multiclass as it opens Sneak Attack and Cunning Action to many martial characters. Yet you have to find a way to attain minimum ability requirement. 

This subclass is based on my previous subclass idea 'Minuteman'.

Bonus Proficiencies

You gain proficiency in Medium Armor and Shield.

Adaptability

You can use Sneak Attack feature even if your weapon lacks Ranged or Finesse property. Also, you can add half of your Dexterity modifier (round up) to the Melee Weapon Attack if that weapon lacks ranged or finesse property.

Once you reach 5th level, you can make a Melee Weapon Attack using Cunning Action if you didn't use and forgo the Sneak Attack feature in that turn.

Aggressive Tackle

By 9th level, you gain advantage on Athletic check when you try to shove a creature

Rapid Response

By 13th level, when you use Uncanny Dodge as reaction and if the attacker is within the reach of your weapon, you can make a Melee Weapon Attack to the attacker as part of that reaction. If the attack hits, the target suffers the weapon's normal damage plus Sneak Attack damage.

Impressive Vitality

When you reach 17th level, your Death Save Throw never fail. And once per long rest, you can choose to make a Death Save Throw roll to be natural 20 and regain half of your maximum hit points.