OK I took my holy sword out by my house and found a ogre i let the ogre attack me with no weapon armed he did 12,12,14 to me i then armed holy sword he then did 24,24,24 to me i kept having to back off so i wouldn't kill it but seems to me it confirms that if you are holding a slayer and fight the opposite slayer you WILL take double damage from them
oh and i hit the ogre for 27,29,29 when i should have been hitting for twice that so they do double to you and you do half to them that explains why when i was in despise fighting ogre lords with holy sword it took forever to kill them and I was nearly killed in one hit with 99 hp and 70 resist suit