Last Raider disappeared

I cannot find the last raider. Curiously, he takes up almost exactly 50% of the raid bar. Is there even a raider mob with that many HP? (Although when I restarted the game, the bar was shown as completely depleted once. After reloading the world again it showed the old 50% completion.)

Ringing the village bell doesn't show me his location either. Is there any way to finish the raid?