HP depletion is the primary lever
The catch probability scales exponentially with how low you push the HP bar. Always deplete to under 30% HP before deploying a Demon Ball.
Stack bloodline multipliers
Picomori doubles catch chance and guarantees hidden monsters roll B+ or better. Exile Celestial doubles the mutated catch path. Stack both before chasing hidden bosses.
Hidden-only perk awareness
Some Bloodline perks like 'Level B Catch Chance 2' only apply when the target is a hidden monster. The Catch Rate Calculator on /tools/catch-rate/ lets you model when a perk actually fires.