While not the most positively received 'batshit insane' boss, I would definitely say Leon's final boss in Resident Evil 6 was insane, and memorable in its own ways.
Fucking Simmons. So he makes no logical sense, he transforms into all of these extravagant things and has something like 7-9 different forms, but always manages to compact back into man shape no matter what he does.
So, what exactly does he do?
He starts off as this dog-like thing who crawls along the inside of the train and the top, you have to use partner commands to reach the top and jump down at the right time, he can suddenly move fast but mostly moves slowly as you shoot him down, you try to get him to revert to human mode so you can punch the shit out of him.
He then throws Leon off the train and suddenly turns into this:
No good pictures of it, but he starts running along the train tracks as fast as the train you're speeding along on, and his back transforms into this turret gun thing that shoots bone-like things at you like bullets. You have to take cover on the train and shoot back as he runs alongside you, and he ultimately comes into the train as you have to fight back.
You run to the top of the train as he destroys the train car, then flips another train coming right at him off a bridge as you guys run across it. He then runs far ahead of you, turns around, and starts charging towards the train car you're on. You need to land a square bullet on his face, and then this scene triggers:
And after a cutscene he seems like he's dead... But no, he's just getting started.
A bit later, you encounter him again, he's in his human form, he rants, and then suddenly he turns into a
motherfucking T-Rex.
You fight him for a while in a arena as he flips over cars, tries to eat you, ram, you, shake the whole area, etc. You have to shoot his eye in his mouth and other weakpoints to get him to turn back to his human form so you can punch the shit out of him again.
Ultimately, a BSAA guy comes by with a jeep and then you drive along with turrets as he chases you.
But he destroys the jeep, and back on your feet fighting him again, but this time more aggressive. You ultimately do take him down, and start to take the elevator but he's transformed again, this time into some... Centaur thing. And he starts climbing up the building after you, leaving you dangling off ropes as he tries to attack you and you have to avoid as you climb the building.
You get off a bit as Ada's arrived on the scene to help her snipe the boss for a while, then climb some more, and get into an arena battle with Centaur-esque Simmons.
He shoots, he sweeps, he does all sort of attack maneuvers and is a battle that utilizes a lot of the game's sliding and dodging mechanics. Ultimately he pushes Leon off the side of a building to cling on as he stamps on his fingers and has a dramatic villain moment, Ada saves him by beating the shit out of him. And together, they take him out with Helena's help.
So he's dead, right?
NOPE.
As you get to the top of the building, he's literally a giant glob now who attacks you with a scorpion-like tail.
He eats zombies to get health and grow and blocks your exit, you shoot him down and get passed him as he does his scorpion-tale attack thing, you get by, climb the building, and suddenly he comes at you as a giant fly.
A. Giant. Fly.
He attacks you as you travel rooftops, and have to shoot his attacks back and damage to stun him, but only stops him for a bit.
You get to a building and see a helicopter, but before you get there, he comes back and it's time for your 'final' fight with him. Zombies are around, he hangs over you, and a knocked-over lightning rod is your key for taking him out in this lightning storm.
You have to stab a zombie with the lightning rod, then damage him enough so he tries to eat zombies to regain health, which will stick the rod to him and get him blast by lightning. Gotta do this a few times, and then he's down.
OR IS HE?
You get to the helicopter, and he climbs back up to you, super weakened now. He's going to destroy the helicopter so you can't escape, but inside the helcioptor there's... You guess it, rocket launchers.
So you shoot him with the rocket launchers, he plunges off the building you've been climbing in an over-dramatic scene, he falls down into the pillar in the center of the arena where you fought T-Rex him and he gets impaled on the pillar.
His blood spills over-dramatically, it falls down the pillar to the floor, and his blood fills out the Umbrella logo.
And he's dead. Only three other final bosses to go (Leon's is by far the most ridiculous, though playing Punch-Out with the Ustanak was rather over-the-top too, and the following speeding elevator scene).
It's memorably, but maybe for the wrong reasons.
Just remember you really do need to throw away those preconceptions about the camera angle and not compare it to Bayo or MGR. It's every bit as good in that regard, and I think it's got one of the strongest final sequences in video games. (I didn't expect Platinum to outdo themselves in the same year MGR released) If you do go back to it and get to operation 009, make sure you've got enough time to blow through the entire thing in one sitting.
