Paul Bitterman (aka Lord Mortimer) is the lead vocalist of Gore Quaffer and is the main antagonist in the game.
Paul was Charlie's best friend. A guitarist since birth, the two of them grew up together and decided to make a band. Eventually they did, but Charlie kicked Paul out of the band that they formed, replacing him with Lester. Resentful, he tried to continue his musical career solo, but was always overshadowed by Charlie's band.
Paul fell deeper and deeper into despair. He got to the point that he sold his soul to the Angel of Chaos and became Lord Mortimer.
Infuriated, he set out to one of Charlie's concerts along with his newfound band, Gore Quaffer. At the nightclub where Charlie Murder was performing, Paul sent his minions to douse Charlie's fans in gasoline. Using the band's pyrotechnic display to set them alight as an act of vengeance.
Lord Mortimer was still unsatisfied, so he along with his band confronted the traumatized and ruined Charlie Murder. Too drunk to fight, Gore Quaffer easily dispatched the band and thus began the events of the game, with Charlie Murder fighting for their afterlife in the depths of the Netherlands before being revived by a group of paramedics.
Paul seems to enjoy drinking wine. As Lord Mortimer he's almost always holding a goblet of wine in his hand.
Origins:Paul is seemingly irish since his red hair and pale skin.
[WARNING SPOILERS BEYOND THIS POINT!]
If the player fails to collect and equip all of Smockula's parts, Lord Mortimer will be the final boss of the game. Defeating him will result in his death, and the zombie apocalypse never really comes to an end. The credits will reveal that Paul and Charlie had in fact been best friends since the very beginning. The duo grew up together until they reached their current age, then Charlie abandoned and discarded Paul.
Paul is always shown to be wearing a hoodie, even as a baby. He also wears a hood as Lord Mortimer. The only times Paul isn't shown wearing a hood is in a painting of Lord Mortimer and Paul's animatronic dummy in the Tunnel of Love ride explaining his feud with Charlie& Company.
His fondness for wine is also shown in the Bad Ending flashback, as he's shown holding a box of it in one scene.
If the player manages to collect and equip all of Smockula's parts, the fight against Lord Mortimer and Smockula himself will end abruptly short. A fiery portal will appear backstage in which the player must travel into. This will lead the player to the deepest depths of the Netherlands. The player must fight through all the demons, imps, creatures, and military personnel to get to the Angel of Chaos at the very end. Defeating The Angel of Chaos will finally end the game.
The credits reveal that after the Angel of Chaos was defeated, Charlie and his band make it out of the Netherlands alive, and the zombie apocalypse actually ceased. Paul is not only alive and recuperating in a Villain Rehabilitation Center, but he has also shook hands after exchanging apologies with Charlie.
[SPOILERS END HERE]
Paul is fought twice in the game. One as Phantom Paul and another as Lord Mortimer himself. The two fights against him are identical, with the difference merely being the latter is a good tenfolds stronger than the former.
Keep moving. Paul is fast for his size and his scythe has a long reach. Staying too close will have him throwing you on the ground over and over again until your health is practically depleted. Staying too far will have him use his dark skulls projectiles against you so the best thing to do is to keep a safe distance where you can hit him but at the same time move out of the way immediately. Lord Mortimer has a curse move that can deal massive damage if it gets you standing still. Having any sort of weapon that has reach is the ideal way to taking down this boss.
However, if you've summoned Smockula, the priority can be focused on him rather than Lord Mortimer if you so choose. Just avoid Mortimer as best you can while hitting Smockula with everything you got. You only have to defeat Smockula to win the fight. The fight, however can be won without battling either foe, as Mortimer deals significantly more damage and has a much higher health bar than Smockula. Since enemies deal friendly fire damage, it's quite possible to get Mortimer to kill Smockula himself using his projectiles while chasing you. Lord Mortimer will be finished upon Smockula's defeat as well, now returned to his original form of Paul.