Duergar:
Dwarven Resilience: You have Advantage on Saving throws against Damage Types Poison, and have resistance to Poison damage.and
Duergar Resilience: You have Advantage on Saving throws against illusions, as well as against being Charmed or Paralysed.I guess you just have to keep on rolling

EDIT: maybe this also comes into play, from Haunted One:
Medicine Proficiency: Gain Proficiency with Wisdom (Medicine) Ability Checks.