Related Clues:

• Person with learning difficulties, but with other extraordinary mental skills — attains void (anag)
• Unworldly person with natural wisdom (French)
• Raymond in "Rain Man," say
• One assumed mentally deficient but who is brilliant in some areas
• One with remarkable skill avoids taint, although corrupt
• One with remarkable ability departs via station on travels
• One surprisingly gifted
• Maybe painter otherwise challenged avoids a tint that's unusual