An alter ego is one who acts in another's absence. Also, there are the following definitions:
1. a second self; a perfect substitute or deputy: His adviser acts as his alter ego during his absence. 2. an inseparable friend. 3. another aspect of one's self. Considering these definitions, Obierika is a true, inseparable friend to Okonkwo. When Okonkwo is exiled, Obierika proves his friendship. He makes money from the yams that Okonkwo left for him. Obierika visits his friend in exile to give him the cowries from Okonkwo's yams and to share disturbing news about the white man who has arrived.
Obierika is Okonkwo's best friend. The two share many memorable moments. When Okonkwo is exiled, Obierika questions the tradition that sends Okonkwo away. Obierika ponders such actions on behalf of his friend. He is a man who thinks deeply about such legalistic measures such as exiling one for an accidental shooting:
Unlike Okonkwo, he is a thinking man. He questions the circumstances that are sending his friend into exile, even while trying to console Okonkwo and taking care of Okonkwo's preparation for departure.
While Okonkwo is in exile, Obierika visits him and shares how the white man has come in to change things in Okonkwo's village and the surrounding villages. He shares how the village of Abame is wiped out by the white men's guns. When a white man arrived on his bicycle, the people of that town did not know what to make of the stranger. Therefore, they killed him and hung his bicycle in a tree. When other white men arrived, they came in Abame and destroyed everyone:
Three white men arrived with a large number of African attendants. They saw the bicycle and left. Several weeks later, three white men and a group of African subordinates came into the Abame marketplace armed with powerful guns. They shot everyone in sight.
When it was nearing time for Okonkwo to come home from his exile, Obierika built new huts for Okonkwo and his family:
At the end of the seven-year exile, Obierika builds Okonkwo two huts and sends for him.
Truly, Obierika is Okonkwo's alter ego in that the two of them are best of friends and inseparable. Also, Obierika acts in Okonkwo's behalf and makes preparations for his friend's return.