On a recent Rest Is History they had a long bit comparing Unai Emery to Lope de Aguirre who went nuts in the South American jungle and killed a load of people in the 16th century, and was then turned into a Werner Herzog film.
I imagine the comparison was picked because they're both from Gipuzkoa and leaders who have inspired people to follow them, rather than Emery's fondness for garroting his employees.