Tsukishima is able to manifest his Fullbring using his bookmark which he can transform into a katana with a tsuba that is the same shape as the bookmark. When Tsukishima cuts an enemy, his is able to split the targets past. He can insert his presence into the history of the victim and they thus begin to recognize him as somebody they are personally close to. The ability even allows him to usurp the role of another person within the targets memory. The victim will thus begin to trust Tsukishima, regardless of their feelings or knowledge about him before being cut by his blade. If their altered past begins to conflict with the reality the targets see before them, it can result in a mental and emotional breakdown. If Tsukishima cuts the target a second time, with his blade, he is able to dispel the effects he created with the initial cut.
Tsukishima can also use his blade to gain information on the target. By cutting a victim, he gains comprehensive knowledge on their past even as he places himself within it. This also works with inanimate objects as he is able to learn about a blades abilities after cutting it with his own. He is also able to alter the history of things like the ground and place traps there that can spring on his current opponents. All these effects are nullified if Tsukishima dies and thus his victims will return to normal.