Fey Child

No folk are more notorious for their trickery than the fey. When a creature twists the slippery magic of the fey with the cunning of mortals, they become known as a Fey Child. This blending could be a result of mixed ancestry, or of time spent on both planes learning from different roguish mentors. It could also be a result of a blessing or a curse bestowed on a mortal by a fey being. Regardless of the origin, the Fey Child learns to weave together strands of energies from the Gloaming Court, the Summer Court, and the chaos of the Feywild to suit their purpose.

A Dash of Air

At 3rd level, you can use your Cunning Action to fey step behind an adjacent creature. When you are within 5ft of a creature, you can expend a Bonus Action to teleport to another spot that is within 5ft of that creature but on its opposite side. (If using grid or hexes, consult the section on Flanking in the DMG pg 251 to determine what counts as an opposite side.)

Until the end of your current turn, that creature cannot make Opportunity Attacks against you, and you can use your Sneak Attack against that creature even if you don't have advantage on the attack roll.

A Touch of Darkness

Starting at level 9, you learn to obscure yourself when in a tough spot. When you take damage, you can use your reaction to summon magical darkness in a 5ft cube centered on you. This darkness disappears at the end of your next turn. You can use this ability a number of times equal to your proficiency bonus. You regain all uses of it when you take a long rest.

A Sprinkle of Summer

At 13th level, you can cast Charm Monster without using a spell slot and without any verbal or somatic components. Once you do so, you cannot use this ability again until you take a long rest. The DC for the spell is 8 + your proficiency bonus + your Charisma Modifer (minimum of 17).

A Recipe for Disaster

Starting at 17th level, when you use A Dash of Air, you may bring forth additional energies from the Feywild to bring the pain to the creature targeted by the teleport. Roll a d4. The result determines what happens to the creature -

[roll]1d4[/roll]
4 The creature takes 4d4 fire damage
3 The creature takes 3d6 cold damage
2 The creature takes 2d8 thunder damage and is deafened until the start of its next turn
1 The creature takes 1d10 psychic damage and your next attack roll against it this turn is made with advantage