Complex sentence: Barnabas was able to use various means, including the I-Ching, to transport his consciousness back into the past in order to inhabit his body in the past; he undertook several trips through time in order to save friends and/or relatives.
Split into simpler sentences: Barnabas was able to use the I-Ching to transport his consciousness back into the past in order to inhabit his body in the past. By doing this, he undertook several trips through time in order to save friends and/or relatives.