Bob must fight all of the game's previous bosses at the same time.
Bob must defeat only two Bosses.
The back-to-back bosses are all underpowered, so the rematches are less hard than the bosses' previous defeats.
Justified: After being defeated in the past by Bob, the three lieutenants wish to exact their revenge on him.
Inverted: Lord Bloodstone separates Bob's team and hunts them down one at a time. You must defeat the same boss with the unique skills of each of the five members.
Lord Bloodstone's lieutenants arrive to challenge Bob to a rematch... only for them to be quickly occupied by Bob's other party members so that he can face Lord Bloodstone right away.
The lieutenants arrive for a rematch, but this time they join forces and fight completely differently.
Bob's friends are defeated, quickly, so he must face Lord Bloodstone's lieutenants anyway.
The lieutenants simply turned Asteroids Monster, and break up into their original selves after taking damage.
Zig Zagged: The climax progresses as follows: the first part of Lord Bloodstone's fight, then Drake's fight, then the second part of Lord Bloodstone's fight, then a Multi-Mook Melee, then Lilith and Skullcrusher at the same time, then a brief dungeon-like encounter, then the third part of Lord Bloodstone's fight.