Hmm ruin delver's fortune isn't discharged. Stacking rules would prevent 3 castings for the different save bonuses though, right?
I was under the impression that wasn't the case, hence why I have 4 castings of energy immunity. Come to think, even though heroics is out on the persist list, with divine power persisted I could cast time stop and then very quickly become take on all of a fighter's class features via multiple castings of heroics.
With miracle as a SLA giving me 4 divine spells of 8th level or lower (of any class, even druid, etc) to persist, I might drop one casting of energy immunity for algid enhancement+mantle of the icy soul. I'd be extending those of course, since they have 24 hour and hours/level durations respectively. I'd be able to eke a +10 to 12 to attack rolls out of algid enhancement. Favor of the martyr is also out, but divine power is still in.
That leaves me one more divine spell. Swift haste is the only thing that comes to mind, but there must be something better out there. Aerial alacrity (wiz4, RotW) gives an untyped bonus to fly speed, it's an appealing option to throw haste in there for a 95' fly speed (stone body cuts the 70' base fly speed of a chronotyryn in half). I contemplated spell resistance, but was shut down by its touch range. I could also throw in lord of the sky (legit because it isn't discharged, per se, you can do something that can cause its duration to end) from Dragon Magic for perfect maneuverability and an extra 5' of movement for a nice even 100' perfect fly speed. If I go shapechange, stone body, lord of the sky, aerial alacrity, and swift haste in that order, I'm pretty sure that's how it'd come out.
edit: yes, multiple castings of ruin delver's fortune is legit, see page 172 of the PHB. The polymorph example indicates that multiple castings of the same spell remain in effect on a creature, and as long as the effects of the second spell don't make the effects of the first irrelevant in some way (like a second casting of polymorph would), you can benefit from multiple castings of the same spell.
edit2: I've just discovered veil of undeath and it's wonderful! I'm now dropping stone body, as its only benefits at this point would be full heals from transmute mud to rock, immunity to spells such as flesh to stone, flesh to ice, etc., and immunity to blindness and deafness. Plus getting rid of the -4 to dex is nice.
Holy star is the current leading candidate for my 4th divine spell to be persisted. Lord of the sky already gives me all day blasting (20 points of sonic via archmage ability), I figured it'd be nice to have a different element as an option. This is marginally better than swift haste, perhaps. It also puts my touch AC up to 69, and with algid enhancement, divine power, and dex my attack rolls are at +44. Saves are at 37/33/40, with another +5 to each against spells.
Still looking for, if possible, immunity to:
Blindness
Deafness
Dazing (buying a third eye clarity, but it's only 1/day)
Sickening
Nauseated
Confused
Not that any of these are huge threats, but if it's as simple as persisting another spell, I'll try to fit it in.
Anything that increases saves, attack bonus, or touch AC is also welcome. Especially if that thing is a dex bonus.