It should be noted that you can make one ice assassin of yourself, then spend your remaining castings to make ice assassins of that, which have no compulsion to kill you. Also that the ice assassin in question in this thread is of an Efreet rather than yourself.
This is stupid. Being a better lawyer than your DM should not give you real, in character power. Just like being a better gymnast, or a better cook, or a better programmer shouldn't. It wouldn't balance planar binding if you had to do more push-ups than your DM before you cast it, it would just make the spell stupid.