As the Original Werewolf, you get bonuses to your ability scores, actions in combat, immunities and resistances, unarmored AC, and the defining feature of the Original Werewolf, its Blood Frenzy. 

Ability Score Increase: You get a +2 bonus to your Strength, Dexterity, and Constitution ability scores. 

Age: As the original werewolf, you age in a similar way as normal humans, however, once you reach the age of adulthood, which would be between 25-30, your physical growth will extremely decelerate to where people would see you as immortal

Alignment: Unfortunately, due to you curse, you nature has been perverted. No matter who you were, you are now a werewolf, a beast, a force of nature and magic itself. Just as how the werewolf brings chaos, you yourself will always be in conflict with yourself. Your alignment must have “chaotic” in this.

Blood Frenzy: This is the most dangerous aspect of any werewolf, especially the first one. In tense situations or in combat, you must make a Wisdom, DC 10/13 saving throw. You cannot chose to fail, however, you can choose to have disadvantage on a save. On a failure, there are multiple effects that take place. There can only be up to three failures, with the third being a complete Blood Frenzy. The effects of stages of the Blood Frenzy stack.

1. First Failure: Stage 1 – Your senses become sharper, however I become hyper aggressive. You have advantage on Wisdom Ability Checks/Saving Throws that involve sight or smell and Strength and Dexterity Ability Checks/Saving Throws. However, you have disadvantage on Charisma and Intelligence Ability Checks/Saving Throws. Inside of combat you must use your action, bonus action, and reaction to calm down. You must wait until the start of your next turn to attempt to enter your Blood Frenzy.
2. Second Failure: Stage 2 – All attacks you attempt have advantage and attacks against have advantage; your speed increases by 10 feet; and any ally within 5 feet of you have advantage on their attack roles (pack tactics). The effects of your first stage of your Blood Frenzy stack on top of the affects you gain in your second stage.
3. Final Failure: Final Stage - Your speed increases by an additional 15 feet; you have disadvantage on Charisma, Wisdom, and Intelligence Ability Checks/Saving Throws; advantage on Strength, Dexterity, and Constitution Ability Checks/Saving Throws; magical conditions like charmed, sleep, poisoned, paralyzed, fear have no effect on you; your Tough Hide AC decreases by 2; you have a damage threshold of 30 while factoring in your damage resistances; all attacks you attempt and or are dealt have advantage; you deal 2 extra damage die per your bite or claw attack; damage rolls of 17-20 are critical hits; and you attack whatever is closest to you. If nothing is near is you, you must use all speed to go to the next living creature and attack.

 Your blood frenzy only ends if you deal 200 points of damage on your turn, or if you are dealt 150 points of damage within 3 turns; by divine intervention; or after 3 full rounds of combat after you entered the final Blood Frenzy stage. Once you exit your Blood Frenzy, you can enter it again, already in the final stage, if you take damage and fail a low Wisdom Save, DC 13. Upon entering your Blood Frenzy for the second time, the damage you deal before you exit your Blood Frenzy drops to 100, damage dealt to you within 3 turns drops to 75, and the turns in combat drop towards 2. Immediately after you exit your second Blood Frenzy, you automatically gain 3 levels of exhaustion.

Cursed Build: Due to your magically enhanced body, you as the original werewolf can carry up to one size larger than your current size with no penalty. This extends even to you other forms.

Cursed Immunities: Due to the duality of the curse bestowed upon the first werewolf and vampire, you are immune to any vampire charm. Any werewolf you sire have advantage on Wisdom saving throws against being charmed by vampires. You are also immune to other diseases and are resistant to poison damage.

Keen Sense of Smell: You can successful track/find beings with a fresh scent and or trail with no difficulty. If you attempt to track/find anything with an older a scent, you will have advantage on Perception checks that involve smell (perception)

Lycan Eyesight:  Because you are inflicted with the werewolf curse, your affliction grants you bonuses. In either of your three forms, you can see normally in non-magical and magical darkness, up to 120 feet.

Natural Skills: Due to your harsh and primal upbringing, you have proficiency in Nature, Survival, and Perception ability checks.

Silver Weakness: Due to the transformation of your genes done by the werewolf curse, you the werewolf garnered tough skin, however, that tough skin also came with a cost: you’re vulnerable to melee or ranged attacks done with silvered weapons

Regeneration: Since you are the original werewolf, you’re made of tougher, better stuff than the other werewolves, which includes your ability to heal. This makes you resistant to poisons and immune to other diseases. Since you’re the original, your healing ability is above average: in combat, if you do not take damage, you regain 2D6+con mod health at the start of your turn; if you take damage you regain 1D6+con mod hp at the start of our turn; and if you take silvered damage, you regain no hp.

Tough Hide: Being a werewolf has its perks. Being the first werewolf has better perks, such as having tough skin. Your tough skin will replace your armor, although you can choose to wear armor and shields, although you can only benefit from wearing the latter. Your Tough Hide AC will equal to 10 + your Con mod + your proficiency bonus. Your Tough Hide also makes your resistant to non-magical damage or damage done by silvered weapons.

Transformation: Out of combat, you can transform into any of your three forms, as many times as you want, while still retaining your abilities and stats. Your size for your hybrid and wolf form is considered large. While in your hybrid form, you stand two feet taller and weigh 150 pounds more. When you transform into your hybrid form, your equipment is transformed with you and any effects are nullified, unless you’re wearing your equipment before your transformation and the effects call for “wearing”.

Wolf Empathy: Being the first of the werewolves, there is respect and reverence due to you from all of the wolf species. You know the general location of any wolf or werewolf within a mile of you. You can automatically identify a werewolf in their human form. You can communicate with any wolf to the best of its ability and they will obey your commands to the best of their ability. You have advantage on Charisma rolls to hostile werewolves.

Actions:

 Transformation: In combat, your transformations will coast a bonus action as the heat of battle riles your bloodlust. All your class and race abilities will be available in either of your forms. In all forms your stats are the same. While in your hybrid form, you stand two feet taller and weigh 150 pounds more. For your wolf form see (Original Werewolf Build). When you transform into your hybrid form, your equipment is transformed with you and any effects are nullified, unless you’re wearing your equipment before your transformation and the effects call for “wearing”.

 Claws:  In your hybrid or wolf form, as long as one hand is free, you can attack with your claw. Your claw will be considered as a martial weapon and magical, as stated in the DMG, and you have proficiency in using them. Your claw attack has a +7 bonus to attack rolls, and on hits your claw attack deals 2D4 + your Str modifier. At 7  and  14 level you gain an additional 1D4 of slashing damage. You can only chain your claw attack as long as one hand is free. You can only chain your claw attack once after a bite attack, once after a pounce attack, and up to thrice total for straight claw attacks.

Bite: In your hybrid or wolf form, you can attack with your nasty bite. Your bite will be considered as martial weapon and magical, as stated in the DMG, and you have proficiency in using it. Your bite attack has a +7 bonus to attack rolls, and your bite attack deals 2D6 + your Str modifier of piercing damage. At 8 and 15 level, you gain an additional 1D6 of piercing damage. On a hit, the target must either make a Strength saving roll, DC equal to 10 + your Str mod + your proficiency bonus or be grappled. If the target is grappled, as a bonus action you can make one claw attack against the target. If the grapple misses, as a bonus action you can make one claw attack against the target. 

 Pounce Attack: If you move 15 feet in a straight line, you can make a bite attack against a target. On a hit, the target must make a Strength Saving Throw, DC equal to 10 + your Str mod + your proficiency bonus, or be knocked prone. The target must make another Strength Saving Throw, DC 10 + your Str mod + your proficiency bonus or be grappled by you. If you manage to knock prone your target, you can make a claw attack against it as a bonus action.