What is the most memorable boss fight you've ever experienced, and what made it stand out?

[Scorpion]

What is the most memorable boss fight you’ve ever encountered, and what elements made it truly stand out? Consider factors such as mechanics, narrative impact, difficulty, music, or emotional connection that contributed to its lasting impression on your gaming experience.

[killamch89]

My most memorable boss fight was in 'Dark Souls', where the relentless challenge, atmospheric tension, and meticulously designed arena forced me to adapt constantly, making every victory feel hard-earned and exhilarating.