Cang Balaurus-Tiefling Assassin/sorcerer

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

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

Sneak Attack. Once per turn, the assassin deals an extra 14 (4d6) damage when it 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 the assassin that isn't incapacitated and the assassin doesn't have disadvantage on the attack roll.

Innate Spellcasting. Cang’s spellcasting ability is Charisma (spell save DC 15). It can innately cast the following spells, requiring no material components:

At will: thaumaturgy

1/day each: darkness, hellish rebuke

Spellcasting. Cang is a 8th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). It has the following sorcerer spells prepared:

Cantrips (at will): chill touch, ray of frost, lightning lure, mage hand, poison spray

1st level (4 slots): absorb elements, detect magic, comprehend languages, fog cloud

2nd level (3 slots): blur

3rd level (3 slots): gaseous form, hypnotic pattern

4th level (2 slots): vitriolic sphere, greater invisibility

Font of Magic. (8 sorcery points) 

Flexible Casting

You can use your sorcery points to gain additional spell slots, or sacrifice spell slots to gain additional sorcery points.

Creating Spell Slots. You can transform unexpended sorcery points into one spell slot as a bonus action on your turn. The Creating Spell Slots table shows the cost of creating a spell slot of a given level. You can create spell slots no higher in level than 5th.

Creating Spell Slots

Converting a Spell Slot to Sorcery Points. As a bonus action on your turn, you can expend one spell slot and gain a number of sorcery points equal to the slot’s level.

Metamagic. Empowered Spell-When you roll damage for a spell, you can spend 1 sorcery point to reroll a number of the damage dice up to your Charisma modifier (minimum of one). You must use the new rolls. You can use Empowered Spell even if you have already used a different Metamagic option during the casting of the spell.

                 Heightened Spell-When you cast a spell that forces a creature to make a saving throw to resist its effects, you can spend 3 sorcery points to give one target of the spell disadvantage on its first saving throw made against the spell.

Strength of the Grave. When damage reduces you to 0 hit points, you can make a Charisma saving throw (DC 5 + the damage taken). On a success, you instead drop to 1 hit point. You can’t use this feature if you are reduced to 0 hit points by radiant damage or by a critical hit. After the saving throw succeeds, you can’t use this feature again until you finish a long rest.

Multiattack. The assassin makes two shortsword attacks.

Shortsword. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 8 (1d6 + 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.

Light Crossbow. Ranged Weapon Attack: +9 to hit, range 80/320 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.