The vampire has taught you how you use a blade.

Return the hit

Also at 3rd level, you become tireless in battle, capable of recovering from injuries without slowing your assault, and your bursts of vigor grant a speed to your attacks that would exhaust other warriors.

When you use your Vampiric resistance feature, you also gain temporary hit points equal to 6 + half your Blood Hunter level, and you can make one extra weapon attack. Once you reach 7th level, you also have advantage on this weapon attack.

Starting 9th level, once a creature you've hit using this ability reaches 0 hit points, you regain your Vampiric resistance.

Vampiric invincibility

When you choose this archetype at 3rd level, you have advantage on saving throws against disease, and you can't gain exhaustion from physical exertion, such as by traveling, sleeping, engaging in combat, grappling or restraining a creature, or lifting and throwing things.

Blood duelist

Whenever you damage a living creature using a melee attack, that creature must roll a Constitution saving throw (DC 12).  On a failed save, you drain one point from the creature's Strength score and transfer it to your own stats (increasing to a maximum of 26 Strength) until the next short rest or long rest.  Creatures brought to 0 Strength by this feature are slain.

If you devour enough strength to bring your strength to 25, then all melee attacks deal an additional 2d6 necrotic damage.

Vampiric parry

At 10th level, you can utilize your blood arcana to dodge incoming attacks. When you are hit with a melee weapon attack and you have a weapon or a shield, you can use your reaction to parry the strike, forcing the attacker to reroll the attack roll and use the new result. If this causes the attack to miss, you can also make one weapon attack against the creature that attacked you as part of the reaction. Once you have used this feature, you can't use it again until you finish a short or long rest.

Tireless mastery

Starting at 15th level, you have advantage on weapon attacks granted by your Vampiric parry feature, and whenever you roll initiative and the feature is expended, you regain the use of it.

Immortal

At 18th level, you become much like him. Unable to die, but unwilling to live. You do not lose consciousness or become incapacitated for reaching 0 hit points via attacks that aren't magical, and taking damage while you are at 0 hit points does not impose any death saving throws. In addition, you can regain the use of your Second Wind feature using your Deathly Vigor feature up to three times between long rests, instead of only once.