For the "I" there's Impact from Real Steel Champions or Ida-Ten from the console game. For the "J" there's Juggernaut from WRB and Champions, Jinko from WRB 2, and Jasper from the console game. For the "K" there's Kong Tron, also from the console game, and Klaus from WRB. For the "L" there's Lothar Shock from Real Steel Champions. For the "O" there's Orefist from the console game or Olympus from Real Steel WRB. For the "Q" there's Quarterback. For the "R" there's Ramchip from the console game, Ronin from WRB/Champions and Royal Camelot from iOS. For the "U" there's Uhuru (aka Spectre) from iOS. For the "W" there's Wildfire from all three games and Wraith from WRB 2. For the "X" there's Xiang from WRB 2. For the "Y" there's Yutu and Yoddha from WRB 2.
Rubicon was a bot who fought noisy boy in 2016 (Said by max himself) Rubicon only won because he got lucky with a huge uppercut that ended noisy. Too bad that there are no pictures of Rubicon but the info is real