This is a reusable preparation checklist rather than a boss ranking. It helps catch common setup problems before you spend another attempt on execution.
Preparation
Use boss-specific help after the checklist
If all preparation boxes are covered but the fight still fails, the issue is more likely timing, positioning or one boss-specific mechanic. Open the relevant boss page next.
Keep preparation proportional
Do not spend more time farming buffs than the fight itself requires. Add preparation only when it solves a repeatable problem.