Minor modifications were made to OverKill for Season 3.0, mainly in the aesthetics department, as Team Coolrobots began a sponsorship contract with Wizards of the Coast who supplied the team's robots with decals advertising its Magic: The Gathering trading card series.
Due to OverKill entering Season 2.0, it was seeded and was able to start in the round of 64 up against the heavily redesigned M.O.E.. For this battle, Team Extreme had constructed a "Voodoo OverKill" out of roller skate wheels and cardboard. M.O.E. drove into OverKill early on, but OverKill got away, taking a hit from the killsaws as it did. OverKill drove around to the side of M.O.E. and pushed it around the BattleBox, but M.O.E. escaped and hit OverKill's wheel with its ditch cutter. However, it did no damage and OverKill continued to push M.O.E. around with its wedge, stopping the ditch cutter in the process. OverKill whacked M.O.E. with its blade and then rammed M.O.E. with the wedge, continuing to use the blade as M.O.E. spun the ditch cutter up to its top speed again. M.O.E. continued to drive after OverKill until it got scooped up by the wedge again, pushed around the BattleBox and whacked by the blade numerous times. M.O.E. finally got the upper hand as it wedged OverKill's blade into the Lexan, keeping it from moving, but OverKill managed to free itself. OverKill hit M.O.E. with the blade numerous times until the fight ended. OverKill won on a 28-17 judge's decision and advanced to the round of 32, where it faced Robosapien
OverKill dominated this fight, getting underneath RoboSapien several times and eventually pinning it under the spike strip. OverKill won by KO at 1:36 and advanced to the round of 16, where it faced FrenZy again.
OverKill won on a close 23-22 judge's decision and advanced to the quarterfinals, where it faced Voltronic.
OverKill won on a 30-15 judge's decision and advanced to the semifinals, where it faced BioHazard.
Much like its previous fight with Voltronic, Christian Carlberg locked down OverKill's blade with the hope that the lower center of gravity combined with sudden forward inertia would make OverKill's wedge lower than BioHazard, allowing OverKill to get underneath. The fight begun with both robots avoiding the hellraisers before OverKill timidly hit the front of BioHazard. OverKill reversed and got away from the front of BioHazard before attempting to line up for another attack. OverKill got its blade stuck on the killsaws momentarily but freed itself before having one wheel land on top of BioHazard. Both robots then kept making contact with each other and OverKill drove itself into the spikestrip before eventually, BioHazard got under OverKill and flipped it into the pulverizer. OverKill suffered one blow directly on its main cylinder but drove deliberately along the side of the spikestrip in order to self-right itself. This worked and the sparring continued for a while. BioHazard then got another flip on OverKill, which resulted in another self-righting maneuver BioHazard then attempted another lift, but OverKill escaped before it was turned upside down. However, OverKill took a hit from the hellraiser and a shot from the killsaws, scoring points against it. Several more flips later, and BioHazard was able to damage OverKill's knife blade on the pulverizer, where it took 3 hits. The fight ended with OverKill being flipped by the piston, and almost taking another flip from BioHazard. Despite being relentless, OverKill lost a 38-7 decision in favor of BioHazard, knocking OverKill out of the competition.
OverKill wasn't finished, however, as it participated the heavyweight royal rumble at the end of the tournament. First it pounds FrenZy, and hits Little Sister. It then goes for FrenZy again, then starts hitting MehcaVore Then it scoops up MechaVore and shoves it into the wall. Then it attacks HexaDecimator. While fighting FrenZy it accidentally flips itself over after driving onto Little Sister. it then attacks HexaDecimator again, who flips OverKill right-side-up. After this it tangos with FrenZy some more. Next it scoops HexaDecimator and rams it into the spikes. OverKill drove onto FrenZy but retreats before FrenZy could attack. OverKill then confronted HexaDecimator again, then is attacked by GoldDigger. Next it attacks FrenZy again, and last but not least it assaults Nightmare. OverKill did very well as it was one of six robots still moving, but lost out to HexaDecimator
For Season 4.0, OverKill received very minor cosmetic changes yet again, receiving new sponsor logos. Due to being seeded, OverKill was allowed to skip the preliminary rounds straight to the round of 32, against Greenspan This fight was fairly uneventful in the beginning stages, until Greenspan decided to follow OverKill towards the red square. OverKill, however, drove over the killsaws in the process, and was tossed backwards by them. This resulted in OverKill hitting the front of Greenspan, throwing Greenspan up into the air, and sending it upside down on its back, leaving Greenspan immobilized. OverKill won by a KO in dramatic fashion.
OverKill's next bout in the round of 16 was up against MechaVore. At the start both robots strafed slowly around each other before MechaVore began chasing down OverKill. OverKill drove over the killsaws, turned, and exposed its right wheel to MechaVore, resulting in Mechavore cutting into OverKill's rim and slicing into its blade. MechaVore then crashed into OverKill's blade again, but this sudden impact stalled its gas-powered disc motor, and wasn't able to work for the rest of the fight. This allowed OverKill to get underneath its opponent before MechaVore reversed itself into the pulverizer, where OverKill pinned it. Mechavore escaped but began having control problems as OverKill drove over the top of MechaVore and flipped itself. Both robots then drove around the BattleBox for a while before MechaVore took damage from the killsaws. OverKill then took control of MechaVore and pushed it into the hazards, scoring points. OverKill continued its aggression and eventually bent MechaVore's disc out of shape. Then OverKill pushed MechaVore back to the pulverizer for a final shot. With 20 seconds left, MechaVore began malfunctioning and spun uncontrollably. Both robots took significant damage from each other but OverKill controlled the match and won on a 29-16 judge's decision.
Overkill pushes M.O.E. towards the killsawsOverKill then moved on to the quarterfinals for a rematch against M.O.E. This battle was close, with M.O.E. doing damage to OverKill's wheels and blade, which it mangled, but for the most part OverKill was unharmed. OverKill, however, was the aggressor, pushing M.O.E. into the hazards constantly (one time almost cut the motor to M.O.E.'s weapon) and out-driving it (OverKill dodged M.O.E. for much of the first minute, wearing down M.O.E.'s battery), and M.O.E.'s saw blade hubs became loose. At one point in the match, M.O.E.'s blade got caught in the rim of OverKill's wheel, and Christian Carlberg gunned it, flipping M.O.E. over. After awhile, the two bots eventually became loose. Near the end of the bout, M.O.E.'s weapon began to slow down. In the end, it was close, but OverKill was given the judge's decision, 25-20, controversially (the crowd massively booed the outcome) pushing OverKill into the semifinals for the second season in a row, this time against Surgeon General, another horizontal spinner. Because of the damage M.O.E. did to the blade, Team Coolrobots had to replace it for the one MechaVore damaged, after fixing it up.
OverKill spent most of the first part of the match dodging the horizontal spinner, but then Surgeon General managed to get some strikes on OverKill's wheels and wedge. Eventually, Surgeon General got its disc caught in OverKill's blade, stopping it. OverKill drove the two of them over the killsaws, knocking Surgeon General loose, but it was immobilized. OverKill won by KO in 1:45. According to Christian Carlberg, of the three horizontal spinners (MechaVore, M.O.E., and Surgeon General) that OverKill faced in Season 4.0, Surgeon General was the one that caused the most damage to OverKill. This win put OverKill to the heavyweight finals for the first time, where it faced BioHazard once again.
Both robots drove out of their squares and BioHazard rammed straight into OverKill, nearly flipping it over. While OverKill swung its blade, BioHazard got underneath OverKill, lifted the arm and headed toward the arena wall, tipping it onto its side. OverKill landed right side up and drove back. BioHazard then took a few hits from OverKill's blade. OverKill drove itself over the killsaws and went straight at BioHazard, flipping itself onto its back again. The flipped OverKill ran into the spike strip in order to flip itself back over. After this, OverKill tried to drive away, but its blade was caught on the spike strip. BioHazard came over and pushed OverKill into the wall, bending its blade. BioHazard then pushed OverKill over to the center of the BattleBox. BioHazard flipped OverKill back over again, but its lifting arm was stuck in the up position. OverKill hit BioHazard several times with its blade before driving over the low profile of BioHazard once again. BioHazard rammed into OverKill, flipping it, and began to push OverKill around. For the rest of the match, both robots attempt to gain an upper hand, but are unable to. BioHazard won on a 27-18 judge's decision and OverKill was declared the runner-up.