Max Tennyson (Classic)/Omniverse

As of Omniverse, Max is the Magister of Earth.
In The More Things Change: Part 1, Max tried to inform Ben on something until the alarm at Plumber Headquarters went off. Max wasn't seen again in this episode, but it was revealed he had sent a new Plumber named Rook Blonko to be Ben's new partner.
In The More Things Change: Part 2, Max, along with Magister Patelliday and some Plumbers, arrived to take away Psyphon and his gang who caused trouble in Undertown. Max also explained to Ben that the reason he paired Ben up with Rook because he felt that Ben was ready to be a mentor. Ben, at first, wasn't fully up to it, until Rook offered him chili fries.
In A Jolt From the Past, Max appeared briefly near the beginning of the episode, where he was upset that Ben was trying to make excuses for being late, as he wasn't working alone anymore.
In Of Predators and Prey: Part 1, Max was seen early in the episode trying to catch a Quartilloptus. Rook aided Max in capturing the alien and Max revealed that he was using the alien in a dish that he and Rook love to eat. Ben informed Max that something was after him and Max asked what Ben should do.
In Of Predators and Prey: Part 2, Max appeared briefly at the end of the episode where he rescued Ben and Rook after they escaped from the explosion of Khyber's ship.
In Outbreak, Max watched as Rook trained with Ben who was using Wildvine. Rook was defeated by Ben who transformed into Humungousaur. Max told Ben that he needed to learn how to defeat his opponents without using the Omnitrix all the time.
 
In Gone Fishin', Max appeared along with Ben, Rook, and Magister Patelliday, who were all going fishing. Everything was going well until large, mechanical robots called Mechaneers captured Patelliday and surrounded the group. Ben managed to defeat the robots as Juryrigg and the three headed to the Mechaneers' headquarters. Max also mentioned that Patelliday can handle himself while he watched Ben defeat Captain Kork. Rook then pressed a button, releasing all of the boats that were trapped by Kork.
Max appeared briefly in Blukic and Driba Go to Mr. Smoothy's where he tried to contact help in order to help stop Trumbipulor.
In Arrested Development, Max helped take Billy Billions into custody. When Billions complained about Ben taking his credit for saving the world, Max responded by telling Billions to act his age and throws Billions in the Plumber's truck. 
In Showdown: Part 2, Max spoke to an angry Pakmar who demanded an apology from Ben for ruining all of his businesses. Max tried to get Ben but noticed that Ben wasn't even on Earth anymore. Max later rescued Ben, Rook, and Azmuth from Malware on Galvan Prime. Max explained that he knew something was wrong when he couldn't find Ben on Earth and recruited Gwen to locate Ben on Galvan Prime. Max then went along with Blukic and Driba to try and fix the firewall to prevent Malware from reaching the core and fully taking over Galvan Prime. Max had to give up his belt buckle and his shoelaces in order for Blukic and Driba to fix the firewall which they successfully did. Max was seen again with his pants still down flying back to Earth along with Ben and the group.
In Ben Again, Max was confused with the sudden mind change between 11-year-old and 16-year-old Ben. Max soon learned from Professor Paradox that it was Eon's doing and he watched as the Bens used Clockwork to make everything right again.
In Store 23, Max chased Liam with Ben. Liam escaped Max but Ben kept up with him as Feedback. Max urgec Ben not to use Feedback as there were other aliens in the area but Ben didn't listen and defeated Liam. Max scolded at Ben for not listening to him and Ben stormed off. Max was seen again at the end of the episode, still angry at Ben for running off earlier. Ben suddenly hugged Max, to Max's pleasant surprise.