How is one Raju one of the most complex characters of Narayan?

It is difficult to compare characters from different novels because each particular novel contains its own sense of fluid dynamics.  However, one can say that Raju is a complex character in that amount of changes he undergoes.  He starts off as a storekeeper and then winds up as a sage.  His evolution takes him from struggling to earn a subsistence to managing a wealthy artist's career to a spiritual dimension where he is seen as someone who possesses other world qualities.  His complex dimensions also reside in how individuals actually view him.  He appears to be genuine and sincere, but there is a streak of self interest that accompanies him throughout his various changes.  He does benefit from the relationship between he and Rosie, and he does benefit from the interaction with the villagers that provide him food.  Raju's complexity is present because it is not really indicated whether or not he is "sinner" or "saint."  The fact that this distinction is not directly stated indicates that he can be seen in a multiplicity of ways, each having some level of validity.