there is a serious bug with skill "einhasad's strike" which is gained by equipping the einhasad's sacred sword during the quest "seven signs, seal of the emperor", namely it cannot be used during the quest where it should(past of disciples necropolis). it returns an error "cannot be used due to unsuitable terms", which seems to be connected with fixes during the last maintenance. imho the skill doesn't identify the location where it's supposed to be used as valid. i want to clarify that i have the sword equipped, and i am inside the dungeon, so it is not my misunderstanding of the situation. re-logging, reequipping the sword, leaving the instance and returning and even taking the quest fresh didn't make any difference either.