The loss at the Battle of Waterloo directly contributed to the end of Napoleon's empire by destroying his last military force, cutting off his political governance, and showcasing the better skills and coordination of the Allied powers.
In the end, Napoleon's fall from glory because of the Battle of Waterloo was due to several reasons: critical military errors, public opinion of Napoleon taking a decline, and the superior skill of the Allied powers. Had Marshal Grouchy decided to go toward the cannon fire, or the French army had better communication, Napoleon may have had a fighting chance.