Ninja

An interesting variation on the underpowered and boring thief class.  Could possibly be treated as a thief who worships Loki or another trickster god/goddess.

Shadow Lurker

Starting at 3rd level, In darkness or areas heavily obscured by other hazards such as fog or dust, you have advantage on all dexterity saving throws and perception checks.

Flinger of Pain

At 3rd level, You gain proficiency with all thrown weapons, if you already are proficient, you have double proficiency.

Faster Hands

Starting at 3rd level, you can use the bonus action granted by your Cunning Action to make a Dexterity (Sleight of Hand) check, use your thieves’ tools to disarm a trap or open a lock, or take the [Tooltip Not Found] action, or to pull out, put away, and swap hands with weapons and items however you choose.

Nimble Feet

When you choose this archetype at 3rd level, your enhanced reflexes let you move over difficult terrain with blinding speed that would shock other people, so difficult terrain no longer costs extra movement.

In addition, when you make a running jump, the distance you cover increases by 1d4 feet.

Superior Stealth

Starting at 9th level, you have advantage on a Dexterity (Stealth) or ([skill]Sleight of Hand[skill]) check if you move no more than half your speed on the same turn.

Tricksters Cloak

Starting at 13th level you are able to suggest to all magical items that you are, in fact, the right class, race, and level to use it properly, provided you know what class, race, and level to use.

This applies to all nonbiological creatures and inanimate objects, as you can convince them to treat you as whatever class and/or race you choose.

Loki's Blessing

When you reach 17th level, you can take two turns during the first round of any combat. You take your first turn at your normal initiative and your second turn at your initiative minus 10. You can’t use this feature when you are surprised.