Shadowblade Assassin

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

Shadow Step. While in dim light or darkness, the assassin can use a bonus action to magically teleport up to 60 feet to an unoccupied space it can see that is also in dim light or darkness. It then has an advantage on the first melee attack it makes before the end of the turn.

Sneak Attack (1/turn). TOnce per turn, the assassin deals an extra 10 (3d6) 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.

Multiattack. The assassin makes two attacks with its dagger or uses its Shadow Dagger twice.

Dagger. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) piercing damage, and the target must make a DC 14 Constitution saving throw, taking 14 (7d6) poison damage on a failed save, or half as much damage on a successful one.

Shadow Dagger (Recharge 5-6). The assassin throws a shadow-infused dagger+6 at a target it can see within 60 feet. Hit: 21 (6d6)  damage and must succeed on a DC 14 Constitution saving throw or be poisoned for 1 minute. While poisoned, the target is also vulnerable to necrotic damage. The target can repeat the saving throw at the end of each of its turns, ending the effect on a success.

Nimble Escape. The Shadowblade Assassin can take the Disengage or Hide action as a bonus action on each of its turns.

1. Shadow Parry (Reaction): The Shadowblade Assassin is a master of evasion. When an attack targets it, the assassin can use its Shadow Parry to blur into the shadows, causing the attack to miss. The attacker must make a DC 15 Wisdom saving throw or suffer a disadvantage on their next attack roll against the assassin.

2. Nimble Dodge (Reaction): With lightning reflexes, the Shadowblade Assassin can nimbly sidestep an incoming attack or spell. It adds +3 to its AC against the triggering attack, potentially causing the attack to miss.

3. Shadowstep (Reaction): In a burst of shadowy energy, the assassin can teleport a short distance in response to an attack. This ability allows the assassin to move up to 30 feet to an unoccupied space it can see, causing the triggering attack to miss.

4. Counterstrike (Reaction): When an enemy misses the Shadowblade Assassin with a melee attack, it can take advantage of the enemy's vulnerability. The assassin immediately makes a melee weapon attack against the attacker, utilizing the momentary opening to strike back.

5. Uncanny Dodge (Reaction): The Shadowblade Assassin's uncanny agility allows it to evade the worst effects of an attack. It halves the damage it takes from an attack or effect as a reaction, potentially avoiding significant harm.

6. Deflect Spell (Reaction): If targeted by a spell that requires a ranged spell attack, the assassin can use Deflect Spell to redirect the spell away harmlessly. The spellcaster must make a DC 16 spellcasting ability check or the spell fails.

7. Vanish (Reaction): When the assassin is hit by an attack, it can use its Vanish ability to immediately turn invisible until the end of its next turn. This allows it to escape the enemy's line of sight and potentially avoid further attacks.