Octobot King II?

[HighColorSunset]

So I just got to the final boss. I played it. I felt like I could win. And then that part came. Y'know, the one with the Rainmaker. Not only have I never used a Rainmaker before, but it's pretty dang hard to use, and hOW ARE YOU SUPPOSED TO HIT HIS FISTS WITH IT!? And all while endlessly moving on a Ride Rail! Maybe if I manage to hop from rail to rail...carrying the big heavy Rainmaker with its big heavy shots...

 

[Yin_]

Um. You just charge it up, then shoot the fists when they come at you. Or I veugley remember a thing where shoot it at him before he shot. I’ll get back to you on that

 

[Gameboy224]

I mean, just hold a charge on the Rainmaker till and opening makes itself known and fire. As with the previous phases, only his normal punches can be deflected, the spinning ones cannot. If you want to hit his fists from afar, you will have to lead your shots. If you don't want to do that, you can simply just let the fist get close and fire the Rainmaker point blank.

 

[Azure ST]

Im going to go way overboard on this so

So I just got to the final boss. I played it. I felt like I could win. And then that part came. Y'know, the one with the Rainmaker. Not only have I never used a Rainmaker before, but it's pretty dang hard to use, and hOW ARE YOU SUPPOSED TO HIT HIS FISTS WITH IT!?

The rainmaker functions like a charger in the way that you charge a shot and then release it, though the actual projectile fired is completely different.
Compared to the one in multiplayer, the rainmaker given in this boss fight has significantly longer range and the projectile travels really fast, so as long as you pretty much fire directly at the target you only have to lead your shots by a little bit at most.

And all while endlessly moving on a Ride Rail! Maybe if I manage to hop from rail to rail...carrying the big heavy Rainmaker with its big heavy shots...

Mechanically, the weight of your weapon doesn't matter when jumping between ride rails. You should be able to jump quickly between the inner and outer rail by pointing your control stick directly towards the adjacent rail and then jumping. There are 2(?) levels (5 & 23?) that use that mechanic a lot. In the boss fight you don't actually need to do this till the end, you can dodge all his attacks with well-timed jumps.

Once the boss is down, a third innermost rail will appear. Wait till you get to where it's parallel with the other 2 and jump to it. Once you've done that,, you don't need to do anything except wait (I think its ends there the first time through, though theres a zapfish doll on replays?)

 

[HighColorSunset]

Nevermind, I figured it out!