Spellcasters who permanently transform themselves into dragons are a staple of more than one fantasy campaign world. Wizards of the College of Dracology are my version of that staple, with Draconic Apotheosis presented separately for Judges who may wish to implement apotheosis into their game more broadly (if only as background or history).
Your stuff is really cool. Thanks for posting it.
I actually had a similar idea for differentiating wizards by dropping one level of mage for thief to make a special power heavy caster (much like the warlock), but I never got around to it.
I think that the cross-breeding rules offer pretty much all you need to turn into a dragon, though they require you to have a dragon on hand and you must be more intelligent than the dragon to maintain control of the new dragon and your alignment could be in danger of going toward the chaos end of the spectrum (unless the dragon is as lawful or more lawful than you). On second thought, pure cross-breeding is a sub-optimal way to turn into a dragon…
I wonder if it might be sensible, though, to make the transformation be to a dragon of the same number of hit dice as the character, rather than to whatever you want to spend or can afford. Or it could go with xp… How many XP does it cost to level up a dragon?
Looking in the transformation section of the ACKS rulebook, you can see the level-up xp costs, based on the number of special powers (arcane casting counts as two by itself). Monsters do not have level caps, but unlike normal classes, their xp costs to level don’t become liniar at higher levels, continuing to double each level. The end result is, if you are a caster who turns himself into a lich or dragon at high level, you can kiss leveling up good-by since level 12 will require significantly more xp than a 14th level mage. Sure, with the near-immortality such forms afford, you can get there, but most of the party will have died of old age.
On the bright side, a high level mage with monster attack progession/cleave, multiple special abilities, and immunities could probably remain relevant for the remainder of the game.