I think the title of this thread says it all. I am looking to add the sorceror spells up to lvl 9 but I have no idea how to get started. If someone could tell me how those three lvl 6 spells were added initially that would be a big help.
The only 6th level spells that exist, I'm told, are Chain Lightning and Wish, and these because they were already around in scroll fashion to serve some other purpose. Moebius made it possible to have higher level spells, but he didn't make the higher level spells. To do so would require all kinds of new graphics animations and what not; quite beyond Co8's capabilities, I would think. They did do Scorching Ray though by borrowing an existing graphic and making a few modifications.
What Gaear said is true, but in poking around in the .dat files, i've found quite a few of the files necessary to add more spells to the game. It looks like the developers made the ToEE engine with the future in mind. Every spell from the Player's Handbook in listed in certain .mes files, but there aren't any visuals or effects coded. Although it's 'Heal', not 'Wish'
I would suggest using the metamagic feats to use up the higher level spell slots. An empowered fireball and cone of cold is pretty wicked. Especially a fireball spell empowered to level 5 and then to level 7.