Three-Tails Chakra: Release

Due to his mysterious connection to the Three-Tailed Giant Turtle, Yūkimaru is able to at least partially control the Three-Tailed Giant Turtle. At first, Yūkimaru can only make an apparition of the beast appear, after taking some of Kabuto's pills. Later, after taking a larger dosage of the pills (combined with Guren's Crystal Release) he is able to make the beast fully appear, but couldn't control it. Later, when Guren is in danger of being harmed by the Three-Tailed Beast, he is able to halt it completely without Kabuto's pills. When Guren seemingly sacrificed her life to save him, Yūkimaru was lost control of himself and used his powers to the fullest which enhanced the Three-Tails strength and rampage enabling it to break through the Four-Corner Sealing Barrier. These could mean that, like Naruto's Jinchūriki forms, this ability is tied to his emotions.