Ante Pavelić (1889 - 1946)
Pavelić became leader of fascist Croatia after it gained independence from former Yugoslavia. He had already established ultra-nationalist and extremely violent Ustache Movement which immediately begun purge Bosnia from its Serbian population. Their tactics were so brutal that even many Italian fascists called them total nuthead. Mussolini too didn't like Pavelić but he saw him being more fit as leader of the country than someone else. Pavelić too favored Catholics on office and practise ultra-Catholic politics. He too purged his regime from several people whom he didn't want and felt threat to his power. Pavelić was too accused from antisemitism but there is not clear evidence if the was or not.
Downfall of Pavelić came in 1946. In 1946 Communists won Serbian Civil War and managed create socialist state. This caused serious crisis in Balkans which almost led to third global conflict only in 30 years. Despite not having permission of Italians strongly anti-Serbian Pavelić begun war against Serbia. Him had clear goal to kill every Serbian, annex the country and settle the place with Catholic Croats. Italians weren't really happy about that. Despite that fascist regimes hated communist Serbia they didn't want WW3. And Bulgaria was too angry about Croatian attacks against Orthodox churches and was worried about its status as local great power. Finally Italians with some opponents of Pavelić decided that him had go. So Pavelić was quickly removed from his office and executed. His regime was rapidly and violently purged and new fascist regime soon withdraw from Serbia and adopted more moderate politics.