Atarus Leigh

Special Equipment. Atarus carries a few magic items on his person that he is attuned to: The Gamblers Blade, a Luck Stone, and a Belt of Comprehend Languages. He also carries Black and Brown Beast Leather +2, a Compression Bow +1, and a Band of Telepathy.

Mutant Nature. Atarus is a mutant, and therefore his creature type is both humanoid and monstrosity. He also has resistance to radiant damage from sources of radioactivity like generators and radioactive land. This resistance doesn't apply to magical damage, damage from spells, or damage sources that don't specify that they are from radioactivity.

Band of Telepathy. Atarus can send telepathic messages to creatures he has cast detect thoughts on.

Assassinate. During its first turn, Atarus has advantage on attack rolls against any creature that hasn't taken a turn. Any hit Atarus scores against a surprised creature is a critical hit.

Favored Foe (4/Long Rest). When Atarus hits a creature with an attack roll, he can mark the target as his favored enemy for 1 minute or until he loses his concentration (as if you were concentrating on a spell). The first time on each of his turns that he hits the favored enemy, he deals an additional 1d4 of the weapon's damage type.

Evasion. If Atarus is subjected to an effect that allows him to make a Dexterity saving throw to take only half damage, Atarus instead takes no damage if he succeeds on the saving throw, and only half damage if he fails.

Sneak Attack. Once per turn, Atarus deals an extra 13 (4d6) damage when he hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of Atarus that isn't incapacitated and Atarus doesn't have disadvantage on the attack roll.

Spellcasting. Atarus's innate spellcasting ability is Wisdom. He can cast the following spells (Spell Save DC 15, +7 to hit), requiring no material components:
At will: druidcraft, mending, primal savagery (3d10), blade of blood and bone (2nd level version), feather field, comprehend languages*, detect thoughts*, suggestion* (only on creatures that have the detect thoughts cast on them)
1st level (2 slots): absorb elements, entangle
1/day: rary's telepathic bond
*Spell gained from magic items

Mutated Fury (1/Short Rest). When Atarus hits with an attack using a weapon, he can roll one of the weapon's damage dice an additional time and add it as extra damage of the weapon's damage type.

Relentless (1/Day). When Atarus is reduced to 0 hit points but not killed outright, he can drop to 1 hit point instead and use a reaction to make an attack.

Multiattack. The assassin makes two attacks with his Gamblers Blade.

Gamblers Blade. Melee Weapon Attack: +9/+10/+11 to hit, reach 5 ft., one target. Hit: 8+1/2/3 (1d8 + 4 +1/2/3) piercing damage, and the target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one. 
At the start of each day, Atarus must gamble with the blade. He chooses a bonus between +1 and +3. The Blade gains a bonus to hit and damage rolls. While the blade applies, Atarus gains a corresponding minus to his death save (-1 for +1 and so on).

Compressed Bow +1. Ranged Weapon Attack: +9 to hit, range 150/600 ft., one target. Hit: 9 (1d8 + 5) piercing damage, and the target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.

Evil Eye. As an action, Atarus can target a creature within 10 feet that Atarus can see. This magical ability, which Atarus calls the Evil Eye, duplicates the duration and effect of the animal friendship, calm emotions, charm person, or hold person spell (Atarus’s choice; spell DC 15), but requires neither somatic nor material components. If the target succeeds on the save, Atarus is blinded until the end of his next turn. Alternatively, Atarus may curse an object for the duration of the spell. Whoever holds the object or has it on their person is considered to have failed the Saving Throw. 
Once a target succeeds on a saving throw against an Evil Eye, it is immune to all Evil Eyes for 24 hours.

Cunning Action. Atarus can use a bonus action each turn to take the Dash, Disengage, Steady Aim, or Hide action.