Teo's partner for life detailed bellow.

Teo's pact Demon is a curious Wraith Slime. it stays very close to Teo and its a bit overprotective. Teo named His Demon Gaze, quite ironic after Teo's Dad thought it up.
the Demon helps Teo out with all his sneaking and thievery, trying to keep him out of trouble”.

Description
Gaze is a large slime like creature with no eyes. due to the nature of Gaze's body he can take a variety of forms but common traits are massive teeth enough to crush stone and large claws easily able to sever limbs.
a hound like appearance is the most common form he is seen in but can choose much more sickening or terrifying forms.

Echolocation
Gaze has 120ft of Blindsight.
cannot use blind sight when deafened.

Using non-visual senses, such as sensitivity to vibrations, keen smell, acute hearing, or echolocation, a creature with blindsight maneuvers and fights as well as a sighted creature.
Invisibility, darkness, and most kinds of concealment are irrelevant, though the creature must have line of effect to a creature or object to discern that creature or object. The ability’s range is specified in the creature’s descriptive text.
The creature usually does not need to make Spot or Listen checks to notice creatures within range of its blindsight ability. Unless noted otherwise, blindsight is continuous, and the creature need do nothing to use it. Some forms of blindsight, however, must be triggered as a free action. If so, this is noted in the creature’s description. If a creature must trigger its blindsight ability, the creature gains the benefits of blindsight only during its turn.

Blindsight never allows a creature to distinguish color or visual contrast. A creature cannot read with blindsight.
Blindsight does not subject a creature to gaze attacks (even though darkvision does).
Blinding attacks do not penalize creatures using blindsight.
Deafening attacks thwart blindsight if it relies on hearing.
Blindsight works underwater but not in a vacuum.
Blindsight negates displacement and blur effects

Sunlight sensitivity
Disadvantage on attack rolls when in bright sunlight.
Bright sunlight is usally between the hours of 9am-5pm outside of these times Gaze can deal with the sun. DM’s discretion.

Alerted Hearing
Advantage on Perception checks that rely on hearing. This applies to all checks that rely on sight as part of blindsight and has no effect when deafened.
You can’t be surprised while you are conscious.
Other creatures don’t gain advantage on attack rolls against you as a result of being hidden from you.
You have a +5 bonus to your passive (Perception) that relies on hearing.

Assassin
Gains proficiency in Dexterity (Stealth). Gains Sneak Attack with a number of d6 equal to the monster’s proficiency bonus

Day and Night
Unless planned for beforehand Gaze starts combat in Teo's Shadow in places that trigger sunlight sensitivity and starts outside of the shadows for all other situations.

Shadow Claw
At Level 1 Gaze can swipe with his claws dealing 1 D6 + Strength + Sneak Dice(5 D6 Once per Turn) OR Total sneak dice slashing Damage.
At level 9 Gaze can use this attack twice when taking the attack action and 3 times at level 15

Shadow Stalker
At Level 1 Gaze can take a Bonus Action to hide when in dim light or darkness. gains advantage on stealth checks when in dim light or darkness

Shadow Walk
At Level 2 Gaze is able to melt into shadows and become one with them for hiding or combat purposes.
During Combat Gaze can take an action to possess one creature’s Shadow, if it is a foe of Teo the creature looses 10ft of moment speed and Teo gains advantage on attacks made against it IF Teo is currently hidden from the target.
If Gaze possesses Teo’s Shadow during combat he gains AC equal to half Gaze's total number of Sneak dice (rounded down)
During a possession Gaze can only use an action to leave the shadow or perform a grapple.
At level 13 Gaze can shadow walk up to 2 creatures at one time.

While Shadow-walking Gaze dose not take damage from attacks, If a creature is unaware of Gaze's presence they won't notice Gaze in their shadow unless their passive perception alerts them (Gaze stealth check against creatures passive perception) Gaze is classified as heavily obscured when shadow walking.
A sudden bright light such as an explosion or a blinding flash will force gaze out of the shadow walk.

Leaching Bite
At Level 3 Gaze is able to bite with a deadly ferocity.
1 D6 Necrotic + Strength + total amount of sneak dice.
The bonus damage from total sneak dice is double at level 13
Heals Gaze for total damage done.
HP is not restored when attacking a bloodless creature (Skeleton, Construct etc) can be used an amount of times equal to half your total sneak attack dice (rounded up) +1 before needing a long rest.

Nightmarish Scream
At level 8 Gaze Gaze can alter his form and let out a blood curtailing scream of agony. All creatures other then Teo that can see or hear Gaze make a Wisdom saving throw of DC 13 + Sneak dice. on a fail creatures are frightened of Gaze. on a success nothing happens.
On a Fail the creature is frightened of Gaze, the creature can take an action to re roll their wisdom save on their turn but not on the first turn after they were frightened.
Gaze cannot perform this skill if incapacitated or in bright light. can only be used once before needing a short or long rest.

Improved Natural Armor
Prerequisites:
Natural armor, Con 13

At Level 8 Gaze's natural armor bonus increases by 1.
Increase Natural Armour by 1 again at level 13