Alexei, Vengeful Captain

Relentless Endurance. When the captain is reduced to 0 hit points but not killed outright, he can drop to 1 hit point instead. He can't use this feature again until he finishes a long rest.

Savage Attacks. When the captain scores a critical hit with a melee weapon attack, he can roll one of the weapon's damage dice one additional time and add it to the extra damage of the critical hit.

Agonizing Blast. When the captain casts eldritch blast, he adds his Charisma modifier to the damage on a hit.

Mask of Many Faces. The captain can cast disguise self at will, without expending a spell slot.

Devil's Sight. The captain can see normally in darkness, both magical and nonmagical, to a distance of 120 feet.

Spellcasting. The captain is a 6th-level spellcaster. His spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). The captain has the following warlock spells prepared:

Cantrips (at will): eldritch blast, mind sliver, mage hand, prestidigitation

1st level (3 slots): arms of hadar, hex, magic missile, shield

2nd level (2 slots): misty step, invisibility

3rd level (2 slots): counterspell, dispel magic

Multiattack. The captain makes three melee attacks: two with its scimitar and one with Dismissal List. Or the captain makes two ranged attacks with Dismissal List.

Hooked Vengeance (Scimitar). Melee Attack Roll: +8, reach 5 ft. Hit: 8 (1d6 + 5) Slashing damage plus (1d6) Fire damage.

Dismissal List (Pepperbox). Ranged Attack Roll: +7, range 80/320 ft. Hit: 8 (1d10 + 4) Piercing damage plus(1d6) Fire damage.

Parry. The captain adds 3 to its AC against one melee attack that would hit it. To do so, the captain must see the attacker and be wielding a melee weapon.