Complex sentence: Sōfuku-ji contains the "Blood Ceiling"; it was stained with the blood of the vassals of Oda Nobunaga's grandson, Oda Hidenobu, who committed "seppuku" during the Battle of Sekigahara after their leader's defeat.
Split into simpler sentences: Sōfuku-ji contains the "Blood Ceiling;" it was stained with the blood of the vassals of Oda Nobunaga's grandson, Oda Hidenobu. They committed "seppuku" during the Battle of Sekigahara after their leader's defeat.