Thanks for the review. Point taken, however you must realize that Sesshomaru did not let on to the humans that his species would go extinct, if he did that he would expose how vulnerable they really are. Right now as the alliance stands it is a economical and trade facilitated venture. To get what he wants he has to be cunning. Forming a peaceful and satisfying union would give him bargaining power when the time comes. But the emperor, prime minister and shogun fears them because they are powerful. He believes that marrying off his sister to the demon leader will give him more security and an eye in the west.