D&D 5E Proficiencies don't make the class. Do they?

[EzekielRaiden]

It's a actually still into 4.

The shadow monk has tricks but hits like a baby.
The assassin rogue hits hard but folds like chair
The vengence paladin has the power and toughness but can't sneak due to armor reliance.

I was forgetting about the Oath of Vengeance, that's fair--but technically speaking, Paladins can wear leather and pump Dex. You just don't have any of the real "shadow" abilities. Either way, we still have a splitting of the archetype into medium-sized chunks: not small enough to nick them all for one character, but not big enough to satisfy the desire. Someone protected enough to take a hit, stealthy enough to sneak in and maybe sneak out, AND able to drop an assassination strike...just doesn't exist in 5e. Multiple classes could pull it off in 4e. It's a sad loss.

 

[Minigiant]

I was forgetting about the Oath of Vengeance, that's fair--but technically speaking, Paladins can wear leather and pump Dex. You just don't have any of the real "shadow" abilities. Either way, we still have a splitting of the archetype into medium-sized chunks: not small enough to nick them all for one character, but not big enough to satisfy the desire. Someone protected enough to take a hit, stealthy enough to sneak in and maybe sneak out, AND able to drop an assassination strike...just doesn't exist in 5e. Multiple classes could pull it off in 4e. It's a sad loss.

It is a sad loss.

That's why I have a Slayer class in my game.

The rough primer is:

HD: 1d12 per level

Proficiencies
Armor: Light armor, shields
Weapons: Simple weapons, martial weapons
Tools: disguise kit, poisoner's kit
Saving throws: Strength, Constitution
Skills: Choose two of Athletics, History, Intimidate, Medicine, Perception, Stealth, and Survival

1. Heroic Slayer: Starting when you first take this class when you hit with a weapon attack, the creature takes additional damage equal to your Dexterity modifier. You can deal this extra damage only once per turn.
2. Death Attack and Critical Defense:
   1. Death Attack 1d12: Beginning at the 2nd level, when you use the Action action with a weapon attack on your turn, you can make a weapon attack as a bonus action. This bonus attack deals an extra 1d12 damage and the damage increases to 2d12 at level 7 and 3d12 at level 12 and 4d12 at level 17. While wielfing a weapon in both hand, you may use your weapon in your second hand for this attack and if you do you have a +2 bonus to the attack roll. Once you use this feature, you must finish a short or long rest before doing it again.
   2. Critical Defense: At the 2nd level, when you score a critical hit or hit a surprised enemy, the euphoria of carnage grants you resistance to all damage until the end of your next turn.
3. Modus Operandi: At the 3rd level you choose your preferred way to cause a death.
   1. Assassin Mode: You get Sneak Attack
   2. Duelist Mode: You get defense bonuses when surrounded or the closest hostile to the enemy.
   3. Shadow Mode: You get Spellcasting
4. Ability Score Increase
5. Mighty Slayer and The Reaper's Ears
   1. Mighty Slayer: At the 5th level, chose one:
      1. Rapid Slayer: You can use Heroic Slayer twice a turn but only once per attack
      2. Wrathful Slayer: When you use Heroic Slayer, it deals damage equal to the weapon die.
   2. The Reaper's Ears: You not only know death, you speak its language. You recognize the words "kill" "death" "murder", "execute", and "die" in any language when spoken. You cannot say these words until you hear them or are taught them if you do not know these languages.