Slot timing
Slot 1 unlocks immediately. Slot 2 unlocks at Player Level 7. Wait until slot 2 is open before rerolling aggressively on a fresh account.
Target priorities
Picomori for hidden monster routes, Sealed Calamity for hatch compression, Exile Celestial for mutated catch. Pick one target and reroll toward it.
Perk text vs tier
After the May rework, perk text matters as much as bloodline tier. A Legendary-tier perk like 'Level B Catch Chance 2' that only applies to hidden monsters is often more valuable than a generic Mythical roll.