Lethiel casts See Invisibility (http://www.d20srd.org/srd/spells/seeInvisibility.htm), which lasts for 140 hours, thanks to her Oracle Domain caster level bonus.  If it should turn out that any of the enemies that she then goes around hitting with her Acidic Splatter reserve feat weren't dead and were merely faking, they take 5d6 acid damage, unless they give themselves away by trying to avoid the attack.