Will something like this work?
Trigger:
- Night Elf AI 1
- Events
- Time - Every 0.01 seconds of game time
- Conditions
- Actions
- If (All Conditions are True) then do (Then Actions) else do (Else Actions)
- If - Conditions
- (Gate (Horizontal) 1163 <gen> is dead) Equal to True
- Then - Actions
- AI - Lock guard position of (Attacked unit)
- Else - Actions
- Do nothing