Introducing Rabbi Avraham Sinai (formerly Ibrahim Yassin), who is an ex-Hezbollah member born to a Shia-Muslim family in Lebanon. He spied for Israel, became quite senior in Hezbollah, then after being suspected of being a collaborator he was interrogated and beaten for months. They even burnt his 8-month old baby boy to death in front of his eyes.
Years later he was provided asylum in Israel where he eventually ended up converting to Judaism and today is a Rabbi living in Tzfat with his new family. He gives lectures about his life working for Israeli intelligence.
What a man he is!
Update: David actually posted about him many years ago.