It can be said that the fifth style, the Immortal Strike, is merely a single sword move.
If you don't succeed, you'll become a martyr.
However, this one strike is something the enemy cannot withstand, worthy of being called a self-sacrificing blow with infinite power.
"Although I have thoroughly understood the five styles of the Sword of Immortal Slaughter, this is in fact just the beginning of this sword technique."
"It can only be considered a beginner level sword technique."
"According to the intent of the creator of the Judgement of Immortals Sword Art, the power of this sword technique is capable of endless enhancement."
"After becoming an Immortal, one can comprehend a variety of Heaven and Earth Laws."
"Therefore, to further enhance the power of the Judgement of Immortals Sword Art, it is necessary to integrate various laws into the sword technique."