This is getting serious!
This article contains spoilers. It might spoil your gaming experience when first playing these games.
Mordekai is a large, floating sorcerer with no legs, wielding a wooden staff with a red crystal ball on top of it. He served Mental for over 3000 years, and was such a good servant that Mental resurrected him. However, as Mordekai had been dead for some time, Mental was quite late in the resurrection progress, and thus has left him a bit brain damaged. Occasionally throughout the boss battle, Mordekai can be heard speaking gibberish in Latin.
His only attack is to teleport in, fire several magic blasts that will spawn enemies when it hits the ground, and then disappear. A few seconds, he will reappear and do the same thing.
At first, the enemies spawned by Mordekai will be weak or lightweight troops, such as the Zorg Mercenary, but the more damage he takes, the stronger enemies he will spawn in. When his health is low, he will spawn in stronger and more dangerous forces such as the Fiendian Reptiloid Demon or Major Bio-mechanoids/
When Mordekai has been killed, all of the enemies spawned by him will die as well.
- The key to this fight is to balance the fight so that an equal amount of time is spent attacking Mordekai and killing the enemies he spawns. This is very important in the final portions of the fight, as he will start spawning powerful enemies, such as the Fiendian Reptiloid Demon. Being overwhelmed by enemies can cost the player the fight in the later stages, but at the same time, focusing on enemies too much is a waste of ammo because Mordekai will keep spawning enemies as long as he is still alive.
- In the area with the little fortification, just before entering the courtyard of the Grand Cathedral, there are re-spawning objects, including power-ups. Take Serious Speed, then Serious Damage and immediately run towards the entrance of the cathedral. When Mordekai is summoned, if you have been fast enough, the effect of the Serious Damage will still be active for some time; use this opportunity to fire with the SBC Cannon or XL2 Lasergun; this way, you can easily deplete about 1/5 of Mordekai's health in a blink of an eye, before he starts spawning enemies.
- In general, the SBC Cannon is the best weapon to use when fighting him. Charged shots do a large amount of damage per hit and can quickly reach him at long or medium range, while spamming uncharged shots is very effective when he is right next to the player.
- The Cannon is also very useful against powerful enemies he spawns in the later stages, such as Sirian Werebulls and Fiendian Reptiloid Demons.
- After an item in his arena has been picked up, it will reappear in a different location. If the player sees a respawned item in a different location while fighting, they should note its location for later.
- The Serious Speed power-ups are very useful, as they let the player dodge the large amount of projectiles enemies will be firing.
- When the 'pink secret' has been enabled, go to the rightmost jump pad and look to the right of the pad. There will be a small hole with a Super Health in it. Grab this because the extra health will be very useful during the later stages of the fight.
- The jump pads can be useful for as a temporary escape from enemy attacks if the player is cornered. Walking up on one will bounce the player slightly up, which will give them enough air to dodge any incoming attacks and bounce them far enough that they can start moving to the other side of the arena.
- If you have a Serious Bomb, it can be used to kill the enemies if you are heavily overwhelmed by them.
- Mordekai's classic staff appears in Serious Sam 3: BFE's model files, but is unused in that game.