Later, Shredder had hired Slashuur to kill the Turtles. The Turtles are drawn to a strange portal in the sewers, which takes them to a post-apocalyptic New York. There, amidst hundreds of Foot Ninja, they encounter Slashuur once more. Fighting in a magical mandala in the sky, the Turtles once again beat Slashuur. Upon conversing about Hamato Yoshi and Splinter, who Slashuur seems familiar with, the Turtles reveal to him that it was The Shredder who murdered Yoshi. This jogs Slashuur's memory, and he reveals that he is an Utrom. Back on his home planet, Ch’rell, who would later be known as The Shredder, slew all of his friends and family, leaving him heavily scarred. Slashuur also realized that he could move across time and space at will, but at the cost of his memory.
Slashuur returns the Turtles to their own time, once again promising to meet again. This occurrence would be when the Turtles took siege to the Foot Clan's freighter ship, The Kuraiyama. Slashuur, along with Splinter and Zog, hold off the massive army of Foot Mechs while the Turtles take care of Shredder. As the flaming Kuraiyama begins to sink, Slashuur teleports the Turtles to safety on a nearby dock. True to his nature, Slashuur indicates that he will meet the Turtles again - this time at the Battle Nexus. When the Turtles do venture to this dimension, they do indeed meet him, and best him in a tournament.
Slashuur's weapon is a large scythe, Gengetsu, which is capable of draining his opponent's life force and using it as his own. After certain conditions are met, he is made playable on the Blue Team, in place of Leonardo.