Design a powerful portrait of Oda Nobunaga, the fierce Japanese warlord

Design a powerful portrait of Oda Nobunaga, the fierce Japanese warlord. He should be depicted in full samurai armor, with a stern and determined expression, looking directly at the viewer. The background should be minimal, possibly a dark gradient or subtle texture, to keep the focus on Nobunaga. The lighting should be dramatic, with strong contrasts to highlight his intense features.