Storm Release Secret Technique: Demon Dragon Storm

Hiruko uses the Storm Release Kekkei Genkai he acquired through his Chimera Technique to produce a massive thunder cloud that can infinitely absorb chakra to grow. He can apparently channel this absorbed energy into the earth, possibly leading to a bigger technique.

Trivia

 * After Hiruko uses this technique, and the focus changes back to him from Shikamaru, his last seal changes from Tiger to Bird. When he reactivates the technique to absorb Naruto's Great Ball Rasengan, he uses the Horse seal instead.