Why is this still believed?

[JLukas]

The requirement for New Game+ is defeating Mammon M.  This sets a storyline flag which is then checked for during the Lavos 3rd form battle.  If set, it calls a special purpose command which activates New Game+

Is it possible to set New Game+ through another path of defeating Lavos?  Maybe.  However, I don't remember finding another place where that flag or special purpose command was used.

[KebreI]

JLukas I know thats not true, The first time I played CT I couldn't make it through the Black Omen at all. It was after getting even stronger on Newgame+ that I was able too.

[idioticidioms]

He's talking about when you fight the Mammon Machine inside the Ocean Palace, not when you fight it aboard the Black Omen.

[KebreI]

If that is so then it may be true.

[Shadow D. Darkman]

Wait a minute: You don't fight the Mammon Machine in the Ocean Palace (unless it's the Black Omen). There's just the Golem Sisters and Lavos, and Lavos you're supposed to lose to.

[idioticidioms]

no, I'm pretty sure you fight it in the Ocean Palace, too. you're making me doubt myself now, lol. I'm pretty sure that you do, because I remember Melchior giving you the Ruby Knife to stab the Mammon Machine with, under the theory that it will destroy the machine, but it doesn't, changing the Ruby Knife into the Masamune and pitching you into battle with the mammon Machine and then Lavos shows up.

[Shadow D. Darkman]

Wrong. You don't ever fight the Mammon Machine in the Ocean Palace, not until the OP becomes the Black Omen. Stabbing it with the Ruby Knife changes said Knife into the Grandleon, and then you are taken straight to Lavos. No Mammon Machine battle.

[Acacia Sgt]

Then that would the event where it is attacked, not necesary a battle against it.

[idioticidioms]

you may be right, but I'm pretty stubborn, so I'll wait until I reach that point in the game again and know for sure before saying anything further at this point.

[V_Translanka]

I'm pretty sure Shadow's right. You just fight it in the Black Omen...Here, check it's Encyclopedia entry...

http://www.chronocompendium.com/Term/Mammon_Machine_(Monster).html

[Shadow D. Darkman]

*nod* I know my CT events.

Question is, is the fact that the Black Omen is the Ocean Palace risen from the waters what confused you into thinking you fought it in the Palace, as well as the Omen?

[idioticidioms]

no, no, I just thought you fought a battle there, too. Should have known better seeing as how I just replayed through the snes version again not too long ago.

[tripehound]

Pulled from the Compendium's CT FAQ:

How do I get New Game +?

Defeat Queen Zeal in the Black Omen, then kill Lavos to win the game. At the end, reset and start a new game. Note that if you already defeated her but gated out of the Lavos battle, you can still fight Lavos and access the new game.

JLukas' response seems the most correct to me, from a programming standpoint. It's either Zeal or the Mammon Machine that has the flag or modifier; I forget which it is specifically.

[Shadow D. Darkman]

Then why is it people have gotten NG+ without doing the Black Omen?

[V_Translanka]

Maybe they are mistaken, their game's memory has been altered, or perhaps like I brought up, that code did more to the game than they were unaware of...