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Old man is the odd, mysterious man appearing from time to time. It seems that irritating Hero brings him specific fun. Old man helps in a curious, sophisticated way.
Old man is a mystery man. Is it not known whether he is a human. His estimated age is about 70 years young (young, not old) but his life energy is enormous. He wanders with his staff (stuff?) but probably he doesn't need it at all - except for creating a proper image.
Character's MBTI Edit
His personality is far beyond any MBTI type (Myers-Briggs Type Indicator) since he behaves in different situations almost randomly. This kind of behaviour suggests strong perceiving type and ability to psychic dissociation.
It is likely that Old man has also strong intuition part but his cognitive functions can be just a mindful projection.