Noblesse Oblige.

The Kirabi vs fish form Kisame fight mainly consisted of Kirabi running away because he was more concerned for the safety of Sabuchan and Ponta. Initially, Kirabi dragged his friends to try to escape the water dome but Kisame can move it at his will to keep them tracked. Kirabi changes directions from Sabuchan and Ponta because he is who Kisame is after, but Kisame keeps going for Sabuchan and Ponta. Kirabi rushes back to save them and Kisame tackles him. Kisame revealed that his going after Sabuchan and Ponta was a feint to catch Kirabi. While in contact with Kirabi, Kisame's body which is infused with Samehada immediately begins absorbing the Hachibi chakra. Kirabi disregards this and grabs Kisame with tentacles from his partial transformation (like Sasuke's Curse Seal level 2), which let Sabuchan and Ponta escape. Nevertheless, Kisame has the advantage in the water dome because he has gills and Kirabi is now running out of oxygen. Kirabi becomes unconscious and Kisame dispells his jutsu as well as his transformation. To make sure Kirabi can't escape, Kisame tries to cut off his legs with Samehada; however, due to absorbing so much of Kirabi's chakra, Samehada changed its loyalty to Kirabi because it likes his better. As a result, Samehada slashes Kisame and begins replenishing Kirabi with chakra like it had done with Kisame previously. Kisame quickly hinders this by kicking away Samehada but Kirabi is now conscious. Kirabi attempts to escape but Kisame grabs Kirabi's own sword to cut of his legs.