Also add official warring to the guilds then, meaning that once you have declared war you can freely attack all their members without AP loss, and hit people of the enemy guild who have 100 AP with your sword.
Or perhaps make those different things options when declaring a war, some of those options could be:
- No AP loss.
- No items loss.
- No additions to global (I.E. Non-guild) kills/deaths count.
- 100 AP enemies treated as if they have normal AP.