The answer is: Necho, King of Egypt

2 Kings 23:29, 2 Chr 35:20-25

Josiah's final encounter was indeed with Pharaoh Necho of Egypt, a battle steeped in drama and tragic consequence. Israel’s last reign of good King Josiah, known for extensive reforms and a deep devotion to God's laws, culminated in this fateful clash. His reforms reinvigorated the worship of Yahweh and abolished idolatry throughout Judah.

By the time he faced off against Necho, Josiah had sought to protect his kingdom from foreign threats, but it was a miscalculation. Necho was en route to assist the Assyrians against the Babylonians, challenging Josiah's intentions. King's Chronicles emphasize an unforgettable moment in Josiah's life: despite being warned by Necho that this was not his battle to contest, he pressed on in courageous defiance. Unfortunately, this commitment resulted in severe injury and ultimately led to his death.

In Jewish prophetic writings and stories, Josiah remains a beacon of faithfulness in his age; is it interesting to note that while his reformations appeared to steer Judah toward renewal, they didn't spare the nation from exile later? This event foreshadows the complexities of adherence and return, laden with an overarching lesson about balance in faith and governance. Some Jewish traditions even regard Josiah as a precursor to the Promised Messiah, emphasizing righteousness under kingship. So, his legacy lives on, reminding us how intertwined faith, leadership, and historical destiny can be.