Instantaneous shadow kill was a high tier assassin skill. Even though the explanation was somewhat similar to the ultimate move of the assassin- death in one strike, the threat was much lesser, like a weaker version of the skill. The skill was flexible, which made it a good learning skill for beginners, it could even be used as an escape tool.
"Theft" needed no explanation. Even though it was not as perverse as Frost Blade's Pillage and it did not have a high success rate, the fact that it could allow the player to obtain free items from others could only be described as BUG-like.
As for Acupoint assault, this skill was a little worthless.
First of all, amongst the seven classes in Rebirth, there was never a lack of crowd control skills. Even Pugilists had the sideway kick to knock their enemies airborne.