Sethine Ironfist (also referred to as Seth Ironfist) is a skill trainer in Might and Magic VIII: Day of the Destroyer. She can be found in her home in the Dragon Hunter's Camp in Garrote Gorge, together with Chadric Benson, and teaches grandmaster Plate Armor.
Her services cost 7,000 gold, and the party member must have ten ranks in Plate Armor first. Grandmaster Plate Armor is only available to Champions.