Dark Release: Inhaling Maw

Hiruko uses this technique through his Chimera Technique in order to forcibly extract the physical and spiritual energy of another ninja and absorb it through the upper square of the mark on his left hand. Much like the Rinnegan's Petra Path, Hiruko does not need to actually make physical contact with the jutsu to absorb it's chakra. Also, it appears that he is able to completely remove the victim's chakra, potentially causing death.

After using this ability, Hiruko is able to detect their natural elemental affinity, and then freely manipulate the victim's chakra element and perform ninjutsu of that element. This allows him to deconstruct and learn the abilities of his opponents, and he can presumably utilize all forms of Nature Transformation as a result.

Trivia

 * Curiously, Hiruko didn't use any hand seals when he first used the technique.
 * When Hiruko tried to absorb Naruto's Wind Release: Rasenshuriken, he was unable to combine the shape and nature manipulation, and the technique fell apart.