What are the feats and class features that turn will and fort saves into reflex saves?
I vaguely remember reading something like this in a D&D 3.5 or PF book.
From 3.5 Epic Level Handbook, p53:
Prerequisites: Dex 25, Slippery mind class feature
Benefit: Once per round, when targeted by an effect that requires a Fortitude saving throw, you may make a Reflex save to avoid the effect (evasion is not applicable).
There is a similar Dexterous Will feat, doing the same for Will saving throws.
Pathfinder has a third party feat from Super Genius Games called Avoid the Arcane, which doesn't make a replacement quite as universal:
Avoid the Arcane (Combat)
Your fast reaction time often allows you to duck magic effects.
Prerequisite: Dex 13, Lightning Reflexes, no caster level.
Benefit: Once per round, when targeted by a spell or effect that allows a Fortitude save or a Will save, you can instead make a Reflex saving throw. You may use the ability a number of times per day equal to 3 + your Dexterity bonus.
Special: If you have this feat and gain a caster level, you may immediately decide to permanently forgo any spellcasting ability and retain this feat. If you do not make this decision this feat is lost, and cannot be replaced.