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Expert Types
From The re-PSUPedia
Expert Classes are a gameplay mechanic in PSU that will allow characters to take on two classes at once.
Details of Expert Classes are very scarce, it having only been mentioned in an interview with Takao Miyoshi in PLAY magazine. Thus, it is not known what the requirements for having an Expert Class will be, what limitations they will impose upon the classes chosen or how the idea in general will work.