I completed the game with a hero in 146 days (it could have been faster, but I wasn't aiming for a record). The map is very good. My strategy was: level up in Darkness + Sorcery + Empathy + Vampirism + Subjugation. My army in the final battle consisted of all native units for the castle (except peasants) + phoenixes. While the enemy is attacking with powerful units, we apply Vampirism to the Vindicators + Subjugation to the Shamans. In the end, all my units died except for the Vindicators (they all survived).