}{0TT@6bI4I see. I took a brief look on all camera files but got scared haha.
Start combat with hero with such skill. Type in console:
combat_camera_log 1
From that moment on, any time a new camera is used in combat, path to its .xdb will be written in console. So when a creature uses this ability, u can catch its camera! 
Its a common way to do it
Thank you very much for your reply.
After deeper testing using the command, it appears the issue lies in the skill's code rather than the camera file.
it always uses the camera file A1.xdb (for any creature size) which is also used in regular melee attacks and works fine there.
I assume the issue happens since the camera always focuses on the "defender", but using Preparation turns the "defender" to the "attacker" code wise, and that's probably the reason the camera cuts off the "defender" here.
Anyway, many thanks!