About the Masamune, and it becoming evil, I have a theory which (I think) no one has come up with. Ok, up until 600 AD, anyone who wanted to wield the Masamune would have to first beat the test of Masa and Mune, first separately, and then their full power. Only Cyrus, and then Crono & Co have been able to beat that test, as before you fight Masa & Mune combined, they say that only Cyrus got that far. We can probably assume that many others had tried for it before, and failed. Now, after Glenn presumably returns the sword to Denadoro, Masa & Mune sleep 'til awakened in CC, although the sword still contains energy stored from Lavos. But the sword obviously isn't in Denadoro at the end of CT, so someone would've had to take it out of there, most likely from Guardia. Ok, now here's where my theory actually comes in: if Masa & Mune are sleeping, then who's there to give the test? Masa & Mune's test was to determine if the possible wielder is worthy and strong enough to use the Masamune, but since they are asleep, the Lavos energy is left uncontrolled, and instead of the normal test, it is more of a test of the wielder's will versus the remnants of Lavos in the sword. Win, and wielder controls sword. Lose, and sword controls wielder, preying upon their fears and evils within their body and mind, and Masamune becomes the demonsword. The sword then stays that way until someone who passes the "test" comes in possession of it, Serge, thereby neutralizing, if not eradicating, the Lavos remnants contained within the sword.