Vasco

Best answer as chosen by Asker / Ratings
About Excalibur: Great Crystal (Srhru Jilaam Pratii'vaa): The only gate required to be opened to access Excalibur is Sagittarius Gate II. When the player reaches this area, there will alway be a chest present, with a chance at a Sage's Ring without the Diamond Armlet, and a Renewing Morion with the DA. After opening the first chest, there is a 20% chance that there will be a second chest right underneath the first one, and will contain the Excalibur. If the second chest spawns, it is guaranteed to be the Excalibur with or without the Diamond Armlet. This is a one-time only chest. If the second chest does not spawn, zone away three areas, then return and try again. Please consult the following map to guide you:
Http://www.gamefaqs.com/console/ps2/file/459841/43190

About Ultima Blade: Pharos At Ridorana:Umbra B2F: Northeast section, easternmost room. Chest has a 30% spawn rate, and is guaranteed to be an Ultima Blade with or without the Diamond Armlet equipped. A one-time only chest. Please consult the following map to guide you:
Http://www.gamefaqs.com/console/ps2/file/459841/45695

Hope I Helped