Fighting Tongue Slash

After focusing Senjutsu chakra to his snaking tongue, Fukasaku then will strike it towards his opponent. Because of the natural energy-augmented chakra built up in his tongue, it will become super-fast and sharp. The tongue can then easily cut through most foes.

In the anime, Fukasaku instead produces a highly pressurized stream of water from his mouth capable of even slicing through metal like Sasori's Water Stream Shooters that can cut through rocks.

Triva

 * "Zessen" is written with the kanji for "tongue" and "battle". It can be translated as to "battle with tongues". In normal use, however, it means "war of words", or "verbal dispute". Just like Fukasaku and Shima are having all the time. The full kanji can be translated as "War of Words Decapitation".