Tales of Phantasia's resident "old man by RPG standards" party member, Claus F. Lester's advanced age of 29 - and lack of Elvish blood - means that he is obligated to handle such menial tasks as planning the group's next task, attending Midgard war councils, and determining the ways in which his fellow party member Arche resembles a tiger.

Unable to cast any magic due to his lack of Elvish blood, Claus has instead taken up the art of summoning. The keys to his battle are his summoning pact ring, each adorned with its own unique gemstone. Not only do they enable him to call upon the power of the ancient spirits to combat his foes, but they also grant him a wide variety of statistical enhancements and elemental protections. By mixing and matching these rings, he can better prepare himself for whatever opponents he may face.