this "species" is designed to be used as an addition to any other species
for example, you could add the Ascendant Vampire species to a Human to get a +1 to all stats and the Ascendant Vampire bonuses.

additionally, this race is not meant to be just selected, becoming even a full vampire after initial vampirification should be a quest, becoming an ascendant vampire should be difficult, take sacrifices, and be a long process.

Vampiric Sense. Just by looking at a creature you can immediately tell if they are of your kind, you automatically know if a creature you are looking at is a Lesser Vampire, Full Vampire, or Ascendent Vampire. 

Supreme Darkvision.

Supreme Darkvision. Your darkvision has a range of 180 feet, instead of 60, and you can see colour in darkness.

Sunlight Hypersensitivity.

Sunlight Hypersensitivity. You have disadvantage on attack rolls and Wisdom (Perception) checks that rely on sight when you, the target of the attack, or whatever you are trying to perceive is in direct sunlight. In addition, being in sunlight causes you to take 1d8 damage per turn spent in sunlight.
Example: if you spend 4 turns in the sun it would look like this: 
turn 1: 1d8
turn 2: 2d8
turn 3: 3d8
turn 4: 4d8
total: 10d8

Spider Climb.

Spider Climb. You have a climbing speed equal to your walking speed. In addition, at 3rd level, you can move up, down, and across vertical surfaces and upside down along ceilings, while leaving your hands free.

Vicious Bite.

As an action you may perform a melee weapon attack using your teeth, if you have the extra attack feature you may use a Bite after a weapon attack or after a Bite attack. The Bite attack uses DEX or STR as it's modifier to both damage and attack roles, and you are proficient with the Bite attack. The Bite's damage is:

1d10 X Proficiency bonus + DEX/STR. (D10's equal to proficiency bonus + DEX or STR)

After successfully landing a bite attack you may use THE SUCK as a Free Action.

THE SUCK. After a successful Bite attack you may suck your target's blood, THE SUCK deals damage equal to your level + your proficiency bonus and heals you for the same amount, the target must roll a constitution saving throw (DC= 12 + Your Level/2), and if they fail then they gain 1 exhaustion point. You can use THE SUCK a number of times equal to your proficiency bonus X 2, and you regain expended uses on a short or long rest. using THE SUCK gives you a Bloodlust point after being used.

Ascendant Bloodlust. This feature only activates once 2d10 Bloodlust points are acquired, the amount required is rolled after each reset of Bloodlust points, IE: activating Bloodlust or losing all points, if you wish you may reroll the 2d10 and must use the new result, you can only lose Bloodlust points if you do all of the following: 
1: spend 1 week without killing any creature.
2: spend 1 week without using a single Bite attack.
3: spend 1 week without using any vampiric powers. (such as walking on walls, or using a vampiric power from this species)

Once you gain all required Bloodlust points, you enter an Ascendant Bloodlust, an Ascendant Bloodlust lasts for an amount of rounds equal to the amount of Bloodlust points required to activate it, with a cap equal to your level. During a bloodlust, you gain the following:

1: On each of your turns, you must spend all of your available actions on Bite attacks, you may choose who to Bite if more than one option is available, although you may not choose how to get to them, it must be the shortest available path even if it results in harm, (such as walking through a fire or into sunlight) if there are no targets in range, or you deal no damage to other creatures on your turn, you take damage equal to the amount of Bloodlust points used to activate the Ascendant Bloodlust.

2: THE SUCK no longer has a use limit, and must be used after a bite attack.

3: You gain an Extra Attack.

4: You gain 25 ft of extra movement speed in all types that you already have. (EX: if you have 30 feet of fly speed it becomes 55 ft, but you do not gain 25 ft of burrow speed)

5: You gain advantage and a +3 on all DEX, STR, and CON saves, but gain Disadvantage and a -1 on INT, WIS, and CHA saves.

6: You lose 1/5 of your AC. (ALT VERSION: You lose half of the AC from your DEX modifier)

7: You cannot cast spells, or maintain spell concentration.

8: You lose the ability to speak or communicate in any way.

9: After each use of THE SUCK you may remove one round remaining from your Ascendant Bloodlust. 

Voluntary Bloodlust. You are able to control your need for blood to a certain extent, as a bonus action, you are able to add or remove an amount of Bloodlust points equal to 1d6 + Proficiency bonus. Once you use this ability you must wait  2d4 days in order to use it again.

Vampiric Domination. Because of your immense Vampiric powers, other Vampires feel the need to obey your wants and desires. All other Vampires that you can see and are within 100 feet of you must pass a Wisdom saving throw (DC equals your level) or become entranced by you, Ascendant Vampires cannot be entranced. An entranced creature must obey all commands you give them. These commands are delivered telepathically, and cannot be longer than one sentence. There is no limitation on the action you force a Vampire to perform, it can be any action they are able to do. An entranced Vampire may roll the Wisdom save again with disadvantage at the end of each of their turns, if they pass the save they become immune to the effect for 3 rounds.

you may command any or all entranced creatures as a bonus action, or as a reaction when an entranced creature attempts to attack you or an ally. 

Misty Form. After dying you gain the ability to enter your Mist Form and become a sentient floating dark mist. In the Mist Form you have an HP count equal to your CON modifier, and you gain a fly speed equal to your walking speed. While in the Mist Form you can only use the dash and disengage actions. While in the Mist Form you may choose to spend one hour building a coffin around yourself like a caterpillar makes a cocoon. During the construction of the coffin you cannot move or take actions. Once an hour has passed, you regenerate your body in it's original state.

Bat Form. You gain the ability to transform yourself into a sentient bat, which has the following traits:

1: Echolocation: You are able to see in a 200 foot sphere around yourself, you can see in perfect darkness, and even see invisible creatures. If you are unable to hear your vision returns to normal.

2: Flight: You gain a fly speed equal to 30 + your proficiency bonus X 5 ft.

3: Size: Your size becomes tiny, and your weight becomes 1.2 kilograms (3ish pounds i think)

Demonic Form: this ability requires some context from the lore of the campaign that this "race" was made for. The lore is as follows (all credit goes to cherquezio the great, i didnt make this):

The first vampire who started it all was a noble ( i think ) who saw how devils and demons were essentially immortal, and wanted to attain such a power himself. So the man made a deal with a devil/demon who gave him demonic/devilish powers, those powers are known as vampirism. From the deal the man needed to eat and drink no longer, instead sustaining himself on the same liquid found within the river styx (blood obv), he also was now deathly "allergic" to sunlight, as the hells never had any to be adapted to. 

Many people followed in his steps, eventually the original path was lost, and vampires could only be created by other vampires. However, one part of the process was never lost, the knowledge of how to become an ascendent vampire. There are many steps, however only the final is relevant here (dm's make your own steps for the process), the final step is as follows:
1: create your demonic sigil, many such sigils exist, each giving a different power to the ascendant vampire, you must draw this sigil in blood.
2: place a wooden coffin in the center of sigil, and rest in it.
3: begin the transformation, this part takes about a day to complete, and is entirely intuitive, each vampire completes this process differently.

once the transformation is complete, you will exit the coffin in your demonic form, this is the form you will forever be tied to, after an hour, you may dispel this form. Any time after the first, you may dispel the form as an action and return to your normal body. While in the demonic form, you physically change to resemble a devil/demon, you become red with horns, but the specific look you have depends entirely on the form you got by using your specific sigil. While there are many many potential forms, i will only be providing 3 as an example.

but before i give the form's stats, i will describe both ways one can enter their demonic form:
1: as a bonus action, you can spend one of your hit dice and deal it to yourself as damage, this will put you into your demonic form. While in this variation of the demonic form, you enter a modified version of the bloodlust, in this modified bloodlust, you can use any and all actions, you do not have a requirement to attack on your turn, and you can speak, and cast and concentrate on spells. Before exiting the form, you must harm at least 1 creature (harm is: damage, curse, charm, etc etc.)

2: by reaching 0 hit points, you instantly regenerate your HP using all remaining hit dice, and enter your demonic form, with a modified bloodlust. In this modified bloodlust, you can cast/concentrate on spells, but you must still harm at least one creature per turn or take damage equal to your proficiency bonus X d20. Additionally, you may not choose which target to attack, it must be the creature closest to you, no matter what. You may leave this form at will after 1d4+1 turns.

The forms: finally it's time to give the examples, as a reminder, these are just examples, you may decide on anything else (with your dm's permission of course)

form 1, sigil of aggression:
while in this form, you gain the following benefits:
1: you may add 1 to each of your mental stats, 5 to your constitution, and 10 to your strength.
2: you gain an extra attack.
3: you gain advantage and expertise on intimidation checks.
4: your size becomes large (roughly 3 meters tall) and you resemble a large ferocious demon. (think of the hell knight from doom eternal)

form 2, sigil of magic:
while in this form you gain the following benefits:
1: you may add 1 to each of your physical stats, and 10 to your spellcasting modifier.
2: when you cast a spell, the effect of the spell happens as if you upcasted it to your highest slot level, no matter which slot you expend.
3: upon entering the form, you can regenerate a number of spell slots equal to your proficiency bonus.
4: your form changes to that of a wizard-y demon. (idk you decide how it looks ig) 

form 3, sigil of expansion:
while in this form you gain the following benifits:
1: you may add 5 to all of your stats.
2: your proficiency bonus doubles.
3: you gain an extra bonus action, and two extra reactions.
4: you gain 4 ethereal arms, which can extend to a length of up to 15 feet, each hand can move on it's own, however they cannot wield weapons, shields, or items weighing more than 10KG, you can dispel and resummon the arms at will.
5: your form changes to more closely resemble a devil in disguise, with small horns and a very faint red tint.