The troublesome aspect of Black Tortoise's ability lies in its capacity to create a group of afterimages indistinguishable from real people. When the truth and the false cannot be discerned, fighting against them would naturally lead to being restricted at every turn. Not to mention sudden attacks like those faced by Zhou Tian, but simply the fear of attacking an afterimage would mean that most of the time, one likely wouldn't retain much strength to face any potential sneak attacks.
If you hold back, you get attacked by the true body; if you don't, you'll be ambushed. In such a situation, without a method to break through the opponent's abilities, standing before Black Tortoise, one would be lucky to exert thirty to forty percent of their full strength.
To rely on Black Tortoise's abilities, now that Zhou Tian can distinguish between the real body and afterimages with his weapon in hand, Black Tortoise's gift has essentially lost its greatest effect.
