The problem with invasions is the accessibility of cracked red eye orbs, and the lack of significant rewards for successfully invading. They should make cracked red eye orbs available for purchase on NG for the normal 10,000 and on NG+ or higher give a discount to the orbs so that invasions are more constant on NG+. They should also give a reward for defeating the host because currently there are no short term rewards from the brotherhood of blood. The reward should be Old Radiant lifegem with a 20% chance of it being an effigy or something similar.