Strength tier: Ares & Achaemenidae < Imperial & Parthian < Civilization. Imperial/Parthian are only ~3-8% better on buff values than Ares/Achaemenidae (buffs ~+3%, debuffs ~+7% per item); refinement caps are unchanged (attack still 25%), so existing refines carry over and need not be redone. Craft at the Forge: Ares->Imperial (Forge Lv30), Achaemenidae->Parthian (needs Forge Lv33, since Achaemenidae itself is Lv33); un-equip first. Cost per piece: Forge Master Certificate (25 for Imperial, 50 for Parthian) + Lv7 red Materials (4 types x10) + 100 Badges + 10M Gold. Set bonuses - Imperial: Attacking Troop Attack 15%->18%, Ground & Mounted Atk & Def vs Monster 25%->30%, March Size 10%->12%. Parthian: All Troops Attack 10%->12%, Monster Atk & Def 25%->30%, Enemy Troop Atk -15%->-18%. Priority: with little Civ gear, upgrade attackers/defenders; with plenty of Civ gear, prioritize a full Parthian set on the MAYOR (debuffs) - it adds 'hundreds of percent' total debuff.
Original research source: Evony Guide Wiki
