Complex sentence: It is likely that Samanosuke was chosen by the twelve Oni gods enabling this, while Jacques was granted power by only one of them, because of this he was only able to transform into one form.
Split into simpler sentences: It is likely that Samanosuke was chosen by the twelve Oni gods enabling this, while Jacques was granted power by only one of them. Because of this, he was only able to transform into one form.