Minecraft wiki entry for damage_type, associated text:  bypasses_armor: Checks if the damage bypassed the armor of the player (suffocation damage predominantly).
 bypasses_invulnerability: Checks if the damage bypassed the invulnerability status of the player (void or /kill damage).
 bypasses_magic: Checks if the damage was caused by starvation.
 direct_entity: The entity that was the direct cause of the damage.
All possible conditions for entities[show]
 is_explosion: Checks if the damage originated from an explosion.
 is_fire: Checks if the damage originated from fire.
 is_magic: Checks if the damage originated from magic.
 is_projectile: Checks if the damage originated from a projectile.
 is_lightning: Checks if the damage originated from lightning.
 source_entity: Checks the entity that was the source of the damage (for example: The skeleton that shot the arrow).
All possible conditions for entities[show]