I'd really like some new champion codes for good champions but also for evil ones if page count allows.
In a book like Secrets of magic, I could totally see magic based reactions.
For example, (Lawful Good option) if an ally is targeted with a spell, I can increase their saves against that spell by 1 at 1st level and 2 at 7th, 3 at 13th, and 4 at 19th. (Just throwing out numbers as an example. Can be rebalanced if too powerful.)
Or (Neutral Good) if an ally is targeted with a spell, you can increase the end result by 1 step.
Or another one, (Chaotic Good option) if an ally is targeted with a spell and saves against the spell, I can capture that spell and throw it back at the caster.
Something similar to this would be both interesting and powerful for champions and it would allow a kind of anti-magic defensive champion build rather than just having anti-physical defensive champion builds.
Perfect book to add new champion options.