What historical event changed napoleon's identity from that of a conqueror to that of a failure?

the battle of borodino

the battle of waterloo

the concert of europe

the coup of brumaire

The event that changed Napoleon's identity from a conqueror to a failure was the Battle of Waterloo.

After the victory in Waterloo the allied troops go into France in search of Napoleon. On July 1, Von Blücher occupies Versailles, on July 8 the crown of Louis XVIII is restored and two days later, on July 10, Napoleon surrenders. He will be exiled on July 26 on the island of Santa Elena, located in the middle of the Atlantic, where he will die six years later.  Napoleon's dream was finally dying, the borders were restored returning to the previous state.

i'm pretty sure it would be, the mediterranean sea.