Viz is the major antagonist of Riddle School 5. He seems to be immune to magma and has telekinetic powers.
Story
Viz started a project called Vizion in which he would decide the fate of every planet starting with Earth. By the time he reached Earth, he has reached the conclusion to erase it from existence. Diz and Quiz, presumably did not want Earth to be erased. In response.
They set up a time-freezing bomb outside of Riddle Elementary School, swaying Viz to try and destroy Earth. After his decision, he went to Riddle Elementary School and captured Phil, Phred, Smiley, and Zack, with intentions using Zack's coldness to freeze Earth.
However, Viz caught all of the kids via a tractor beam and trapped Zack in a chamber which powers a giant ice laser pointed towards Earth. As it gained power, Viz surveyed in his own ship nearby. But Phil managed to turn the laser, pointing it to Viz's ship and freezing him and his ship. A floating asteroid then came and smashed into the ship, shattering it into pieces and killing him. (If he wasn't dead already.)
Riddle Transfer 2
Viz was mentioned by a quick summary made by Phil in Riddle Transfer 2. It figures that he (used to) own Zone 5.1.Then Diz used his ship to freeze Earth.