If I'm reading the Japanese wiki properly (I don't know Japanese and rely on Google translate), it looks like the level 25 reinforcement that drops armors gives two of the best armors in the game. Seiryuu Armor looks like it's 35% damage reduction, with a 30% chance of an extra 15% damage reduction. You have to get four of the other armor it drops to craft them into Ultimate Western Armor, but that gives +20% troops.