The Boss Normalize & Distort flag applies some randomization to boss stats and allows weaker bosses to offer more challenge.

A threshold is set for each stat:
speed = 70, vigor = 24, accuracy = 100, evasion = 0, magic evasion = 0, defense = 150, magic defense = 160, magic = 16

HP and MP thresholds are per level to account for scaling:
HP/level = 500 and MP/level = 150

If a 25% increase in the original stat value is greater than the above thresholds then it is used as the max value. Otherwise, the threshold is used as the max value.
The min value is a 25% decrease in the original stat value.

The new stat value is randomly selected between the min and max values using a uniform distribution.

HP and MP increases are capped at triple their original values so enemies such as right/left blade, hidonites, speck, etc… typically remain easier to kill than the “main” boss.

Early boss HP adjustments are still applied after the normalize and distort bosses flag.