Note: Spoilers for the game Ni no Kuni in the upcoming story. Spoilers for many other games possible in the responses.
My wand is fully powered. My familiars are powerful enough to destroy everything I've come across in the world. Oliver's true potential has been unlocked. The mana threatening the world has dissipated. The castle of the White Witch is all that remains. I've loved every minute of my journey so far, and I can't wait to see the ending.
I proceed through the castle with little to no effort. My enemies fall one by one to unstoppable sword and maddening meowing of my Puss-In-Bouts. Finally, I reach the witch's chambers. After a short conversation, the battle begins. I go through her first form. Then a second. One last battle to go. It begins, and my party is wiped out in about 2 minutes.
I take a break. The next day, I spend more time running throughout the castle, grinding in hopes of being able to defeat the final boss. After two hours of this grind, I try again. Nearly the same results. This cycle repeats itself a few more times.
Ni no Kuni now sits on my shelf, unbeaten. The disappointment I feel every time I look at the case enrages me. My favorite game so far this year, and I can't seem to beat the damn final boss. Which brings us to today's topic. I'm sure many of us, if not most of us, have a story of a boss in a game that we just could not beat.
This is one of mine. What are yours?