Archafflictor

Plaguebearer. If the Archafflictor successfully hits a creature with a melee attack, it can transfer any negative magical or nonmagical conditions currently affecting itself onto the target. The target is then subject to those conditions for the same remaining duration that they would have affected the Archafflictor. If any negative conditions can be resolved by succeeding on a saving throw, the target gains the ability to do so as well.

Adaptive Spellcaster. If the Archafflictor is affected by an effect that would increase it's critical range, it's Attack DC's increase by the same amount.

Backhand. Melee Unarmed Attack: +4 to hit, reach 5 ft., 1 target. Hit:  (2d4 + 2) bludgeoning damage +  (1d4+3) poison damage.

Infestation.The Archafflictor conjures a cloud of hungry insects that feed on disease on a point it can see within 30 feet. Each creature within a 5 foot radius sphere of that point must make a DC 15 Constitution saving throw. On a failed save, the creature takes 1d6 poison damage and bludgeoning damage plus an additional 1d6 poison damage for each negative condition currently affecting it.
On a successful save, the target takes half damage.

Miasma. The Archafflictor targets one creature it can see within 60 feet of it. The chosen creature. becomes the center of a noxcious miasma with a 5 foot radius. Each creature, including the chosen one, must make a DC15 Constitution saving throw. on a failed save, the target takes 18 (4d8) poison damage and aquires all negative conditions currently affecting the chosen target (if applicable; the chosen target only takes the damage). On a successful save, the target takes half damage and suffers no further negative effects. 

Vilerot. The Archafflictor spreads a virulent disease to a creature it can see within 60 feet. The target must make a DC 15 Constitution saving throw. On a failed save it takes 12 (2d8+2) necrotic and 12 (2d8+2) poison damage. Additionally, if it fails the save by 5 or more, it is afflicted with one of the following conditions for one minute, determined by rolling a d20.

1. Blinded.
2. Deafened.
3. Silenced.
4. Poisoned.
5. Charmed.
6. Stunned.
7. Prone.
8. Enraged (the target must attack the closest creature on it's turn if possible).
9. Petrified.
10. Asleep.
11. Paralyzed.
12. Frightened.
13. Slowed.
14. Disadvantage on Strength checks, attacks and saving throws. 
15. Disadvantage on Dexterity checks, attacks and saving throws.
16. Disadvantage on Constitution checks, attacks and saving throws.
17. Disadvantage on Intelligence checks, attacks and saving throws.
18. Disadvantage on Wisdom checks, attacks and saving throws.
19. Disadvantage on Charisma checks, attacks and saving throws.
20. Maximum Hit Points reduced by 2d8.

On a successful save it takes half damage and suffers no additional effects.

Plaguestorm (Recharge 6). The Archafflictor unleashes a devastating Whirlwind of disease with a 30 foot radius, centred on itself. Each creature of it's choice within that area must make a DC 15 Constitution Saving throe. On a failed save it takes 24 (4d8+4 poison damage, unless it is the Archafflictor itself, wich, regardless of success or failure, always takes no damage.
After determining the damage roll a d4 for each affected target (successful save or not). On a roll of 1 or 2, the target is afflicted with one of the conditions as describe in Vilerot.
Creatures within 10 feet of the Archafflictor have Disadvantage on their saving throw and are afflicted on a roll of 3 aswell. Creatures within 5 feet have an additional -1 penalty on their saving throw and are afflicted on a roll of 4 as well.
On a successful save, the target takes half damage and suffers no additional effects.

Adaptive Aegis. When the Archafflictor is hit by a magical attack, it can use it's reaction to gain resistance against the triggering damage type for five rounds.