The lone creature needs to occupy a different space--probably only once--, but it needs to be in that different space now, while it would normally be flat-footed, after an attack's made against it but before that attack's resolved.
The creature needs 2 things: it needs 1) to avoid being flat-footed 2) to occupy a different space before an attack resolves (probably via an immediate action or an off-turn non-action). Ideally, a cheap, slotless item exists for each but 1-3 feats or expensive items are acceptable alternatives.
- More than a 5-ft. step is preferred, but 5-ft. steps are still awesome, thanks. Such options must note that the 5-ft. step is explicitly an extra 5-ft. step, though. Many feats don't note this (e.g. Evasive Reflexes (ToB 30), Orien Battle Stride (Dra 143), Pursue (ECS 58)) making it unclear if their mentioned 5-ft. steps are in addition to the single 5-ft. step the creature can make each round (PH 144). I'd prefer the handful of feats that grant explicitly extra 5-ft. steps (e.g. Sidestep (MH 28)) to avoid discussions of text over intent. A way to activate those effects off-turn remains necessary.
- Class levels are unacceptable unless the class level’s benefits grant equivalent or better bonuses than taking 2-4 additional monstrous Hit Dice.
- No custom magic items. Both spell completion and trigger items are fine.
- The spell contingency [evoc] (PH 213) and the feat Craft Contingent Spell (CAr 77) are unavailable.
- Sources limited to Wizards of the Coast material.
Here's what I found.
- The 3rd-level meditation Domain spell that art thou [div] (“The Mahasarpa Campaign Setting: A Campaign Option Web Enhancement for Oriental Adventures” 8 here) via wand (3rd-level spell at caster level 5) (112 gp 5 sp per charge), via wand and affected by the feat Extend Spell (PH 94) (3rd-level spell but 4th-level equivalent at caster level 7) (420 gp per charge), via spellcasting (PH 129) affected by the feat Persistent Spell (CAr 81) (3rd-level spell but 9th-level equivalent at caster level 17) (1,530 gp) and Shalantha's delicate disk [conj] (LE 33-4) (6th-level spell at caster level 11) (860 gp) (unsure if a persistent that art thou fits in a disk though), or via staff affected by the feat Persistent Spell (CAr 81) (3rd-level spell but 9th-level equivalent at caster level 17) (2,295 gp per charge +300 gp per masterwork quarterstaff; 4 lbs.).
- The feat Brand of the Nine Hells (Dispater) (FC2 81).
- The 8th-level time Domain et. al. spell foresight [div] (PH 233) via staff (8th-level spell at caster level 15) (1,800 gp per charge +300 gp per masterwork quarterstaff; 4 lbs.).
Immediate Action Space-exiting
Here's what I found.
- The magic item shadow cloak (DrU 101) (5,500; 1 lb.).
- The conjurer specialist wizard’s supernatural ability abrupt jaunt (PH2 70).