Chief Librarian Mephiston, Lord of Death

If Mephiston kills an opponent in close combat, make a Leadership test on 2D6. If he fails he may do nothing else until he makes another succesful Leadership test at the start of one of his future turns. 

If he is in combat with multiple enemy models he does not need to test until all enemies are slain.

If he is charged while in this state, he becomes Frenzied (Warhammer Rulebook Pg. 67). While Frenzied he is not subject to the Blood Greed rule.

At the start of a close combat round, Mephiston may attempt to 'transfix' any one model he is fighting. The model must make a successful Leadership test on 2D6 to avoid Mephiston's gaze. If this is failed the model is transfixed and has its WS reduced to 0 in the ensuing combat.