Short answers, pulled from the story.
Michel Ney was a French Marshal of the Empire who served under Napoleon in the French Revolutionary and Napoleonic Wars. Napoleon gave him the title "the bravest of the brave" for commanding the rearguard during the retreat from Moscow in 1812, particularly for his nighttime crossing of the Dnieper River under fire after being cut off at the Battle of Krasnoi.
Michel Ney was executed by firing squad in Paris on the 7th of December 1815, near the Luxembourg Gardens. He refused a blindfold and exercised the right to give the order to fire himself, reportedly saying: "Soldiers, when I give the command to fire, fire straight at my heart."
Ney was tried for treason because, after pledging loyalty to King Louis XVIII and organizing a force to stop Napoleon's return from Elba in 1815, he switched sides and joined Napoleon on the 14th of March at Lons-le-Saulnier. The Chamber of Peers convicted him on the 4th of December 1815, with 137 votes for the death penalty.
Ney commanded the left wing of the French Army of the North at Waterloo on the 18th of June 1815. He ordered a mass cavalry charge at around 3:30 p.m. that overran Allied cannons but failed to break the infantry squares due to a lack of artillery and infantry support. He had five horses killed under him during the battle.
At Fontainebleau on the 4th of April 1814, Ney served as the spokesperson for the marshals who demanded Napoleon's abdication. When Napoleon declared that the army would obey him, Ney responded: "the army will obey its chiefs." Napoleon then abdicated.
After being cut off at the Battle of Krasnoi in 1812, Ney led approximately 3,000 men on a night crossing of the Dnieper near the hamlet of Alekseyevka. The river was 110 meters wide and only frozen for a couple of days; the ice broke in several places and 2,200 soldiers drowned. Ney reached Orsha with between 800 and 900 survivors.