The Blue Bullet abilities Mighty Guard and Absorb can be learned from this fiend. Haizhe is not particularly threatening, though in Oversoul it uses all three levels of elemental magic. Elemental-resistant equipment and abilities are recommended to take on the Oversoul version, or Shell or a Lunar Curtain.
Using Lightning-elemental attacks will quickly bring it down.
The Haizhe the player catches informs the party that he is in leagues with a Deep Haizhe whom he calls the "Old Man". Together they plan to protest the use of machina that destroy the environment. When released, the Haizhe meets up with the Old Man at Besaid, and they use a collection of machina to try and convey their message to humans. However, the humans do not understand them and tell them to go away. The Old Man decides to exact revenge on the humans, and the player must catch and raise a Deep Haizhe to finish the story.