I've tried it all. Nothing works. This is not a possible scenario in the game. I become kind of obsessed with the idea of Magus fighting Magus when I saw a Game Genie list with a wall walk code and a procedure to set this showdown up. It was obviously bullshit. The programmers designed damn near ALL the switches in the game to fire off to keep up with where you are, so when you run off to walk through the sealed door get the Epoch when you first arrive in 2300 AD, go get Magus from 12,000 BC, and come back to 600 AD, the damn castle is already beaten. I tried going back to see if I could activate older events to try and reset the switches, but nothing's worked. To get around this, I spent hours using random warp codes through doorways which throw you around different maps of the game trying to find a link someplace into the map of Magus's Castle. No dice. The closest I've gotten is Ozzie's Fort. If anyone has had any more luck than I have getting this to work post that shit here!