In the scenario, he appears right after the British lost their first Castle and attacks the player's base. Fastolf is portrayed as very arrogant, frequently mocking Joan and the player's army. When he dies, he says 'I die for England!'
He is a cavalry hero and is also available in the Scenario Editor. Sir John Fastolf has the appearance of a Knight with a lance, similar to several other hero units. As a hero, he cannot be converted and can regenerate health (since The Conquerors).
Apart from the Line of Sight, John Fastolf has the same stats as Joan of Arc.
Even though John Fastolf can be killed in the scenario, in reality he escaped the Battle of Patay, which resulted in his tarnished reputation of cowardice, and it took 13 years to clear his name.