User blog comment:AaronHW/War of Sons/@comment-24169020-20130407032612

They weren't in War of the Sons, they were in Rite of Passage...Obake are animals that have special qualities that are able to destroy Oni....while Harpies are winged creatures that eat people and are typically kind of withdrawn so....no weaknesses for Obake was stated but Harpies are killed by fire.