"To defeat the Demonic Void, one must kill it before its adaptation ability is activated."
This attack cannot be something the Demonic Void has seen and adapted to before; it must be an ability it has never encountered.
Once it has seen or endured an attack, it will adapt to it. Even if it hasn't fully adapted, it can significantly reduce the attack's effectiveness, making it hard to inflict any substantial damage.
"Even if it hasn't seen or endured the attack, if the attack's power isn't strong enough, it won't be able to deal with it either."
Because it has powerful regenerative abilities, even if sliced in half, it can rapidly regenerate and recover, making it extremely difficult to kill.
This forms a seemingly perfect cycle.
Any attack that lacks the power to instantly kill the Demonic Void, once used, will be slowly adapted to by the Demonic Void, becoming ineffective and even countered.
