Ok, so to review, what could have happend to Melchior.
One major issue is, does he even remember the events of CT during 12,000 BC, or does he forget due to time bastard?
I do think this would greatly influence what he would do during 1005AD, but seeing where he is at the end of CT, I do not think it matters overall.
Is he already dead?
Although some of you believe he is, and it is possible he might have had horrible health, I somehow doubt he kicks the bucket in five years. Maybe in twenty. He did not seem to be in bad health.
Lucca burns orphans as part of her plan 
? "How the hell did we get there? 
"
We really need a sequel.
A new question just came to mind, when did Melchior appear from the gate? I doubt he built a house and several dozen swords to sell at the fair in less then a few days.
My guess is that he would have been there for [600AD Magus's age] minus [12000BC Janus's age] amount of time.
So if Magus is like 32 and Janus was 8 when he was sent back in time, it would be 24 years.
It makes sense: by the time Crono meets Belthasar, he is pretty much on the point of death.
Melchior has a house and seems to be accustomed to a whole new way of life.
Can't say much for Gaspar, the EoT is strange.
And I don't believe Melchior recalls the new version of 12000BC, unless you don't like using TTI and TB.
That cake was sitting there for 24 years? I'm glad I never ate it :p. Anyway, now that brings another question, how old was Magus? I always assumed he was in his mid twenties, since most Jrpgs have a taboo for having someone older then 25 as a main character.
Anyway, true, Belthasar was indeed at the point of death, I have actually considered this, however, he was also alone and was starting to go senile/insane possibly due to loneliness "or how Cross puts it, he always was insane :p". He might have been in the future, but most of the equipment there where well worn/rusted, not to mention the possibility he may have developed other medical problems that could have surfaced in the diseased ridden future, that leaves you hungry
. "How Crono and Co didn't get sick or without mutating we may never know :p ." Melchior on the other hand, did have access too physicians. Granted we don't know how well doctors in that time line could cure people with ethers
, or if magical spells like cure work outside restoring hit points.
Also, that Belthasar in Cross was indeed able to live healthy for some time in 2300AD "they probably cured cancer by then". He also seemed to have access to better equipment. Granted he might have simply built the Neo Epoch and began warping through time almost immediately.
The thing I find confusing about Melchior is that he never says about remembering the new or old events. If you did indeed change his history, and there by changing his memories, he might have remember telling you all about it, or even asking you questions about saving him when you did see him "for the first time".
I actually think time travel immunity applies here. What I mean is, Crono talks to Melchior at the fair about, lets say swords, Crono goes back in time and changes 12,000 bc, Crono comes back to the present, but Melchior doesn't mention it because now that Crono has changed the past, back then when Crono was at the fair buying swords from Melchior, Melchior did ask or tell him about 12,000bc, and since he had already asked, he would have no reason to bring it up again. Crono, under TTI and TB, would not remember this conversation.
Although, the real solution to this probably was the fact there where several writers each with their idea of time travel.... So time it's more like a big ball of wibbly-wobbly, timey-wimey.
