First of all, the immortal mode in Longdi Cave. Taking Yakushi Kabuto as an example, the basic increase brought by the immortal mode in Longdi Cave is the perception and the use of natural energy. However, the immortal mode in Longdidong directly taught the technique of Bai Ji and inorganic metempsychosis, which is relatively normal, but the technique of Bai Ji can be regarded as the skill of killing 1,000 enemies and damaging 800 people. Although the cornea of the snake can shield the strong light, the vibration of Bai Ji should have been affected even by the performer. Fortunately, Dou transplanted the liquefaction ability of Shui Yue, otherwise the technique of Bai Ji would really have an impact on both sides.
This may be related to the negative effects of the immortal mode in Longdi Cave. For details, please refer to Jyuugo. Although the immortal mode in Longdi Cave will increase strength, it will bring grumpy and crazy personality.
The immortal mode of Longdi Cave is the power of snake immortals. In Xiaobian's opinion, his ability is mainly based on natural magic, including Yakushi Kabuto's ability. From the battle between Yakushi Kabuto and Uchiha Itachi, we can see that it includes inorganic metempsychosis, white-excited technique and so on. We rarely see Yakushi Kabuto using any immortal methods such as body art, and every time he uses them, he basically uses ninja techniques such as fairy art, and these techniques have a strong interference with the senses of people and enemies.
The earliest fairy model of Miaomushan did not set any unique ability (perhaps the frog group hand and so on). The fairy model of Miaomushan focused on how to integrate natural energy into its own ninja system to increase the existing ninja power.
To make a simple analogy, the immortal mode of Longdi Cave directly brings the performer multiple skills to enhance the attack system; The immortal mode of Miaomushan focuses more on how to let learners learn to integrate natural energy into their existing skills to strengthen themselves.
Moreover, in terms of time, the setting of the magic system in Longdi Cave came into being because of the magic of Wanke Uchibo clan. Miaomushan, on the other hand, has no such special setting, and naturally it is not as bright as the fairy model in Longdi Cave. (also to give the ferret one last chance to be supernatural)