The Bulgarian Empire was a major force of southern and eastern europe, but fell into disarray and decline with the mongols and other invasions. It made recovery- albeit as a heavily decentralized state- in the 1300s... before being conquered by the ottomans in 1396. Your goal is simple: secure the Bulgarian power in the Balkans with a POD after the mongol invasion, and have it be a great power into the 1500s. They also need to control constantinople before 1492
Bulgaria in the 1240s under Ivan Asen II and their minimum European territories
Bulgaria in the 1240s under Ivan Asen II and their minimum European territories