I was reading the spell plundered power and thought "Hey, free SLA's? This is pretty cool".... Until I re-read and I saw the bit about the Duration and the first line of the description.
School necromancy [evil];
Level cleric 7, druid 7, occultist 6, shaman 7, sorcerer/wizard 7, summoner 6, witch 7
Casting Time 10 minutes
Components V, S, M (crushed rubies worth 2,500 gp and a major organ from the sacrificed target, see text)
Range close (25 ft. + 5 ft./2 levels)
Target one creature
Duration 1 day/level
Saving Throw Will negates; Spell Resistance no
You must sacrifice a creature just as you finish casting this spell.
When the sacrifice dies, its blood or ichor pools and hardens into a single red bloodstone. This bloodstone contains the essence and spirit of the sacrificed creature, allowing anyone holding the stone to activate the creature’s highest-level activated racial spell-like ability, taking the actions necessary to activate the stored spell-like ability. Any creature who holds the stone can activate it, but the stone can be used only once per day (or the frequency of the creature’s spell-like ability, whichever is less). If a creature has several racial spell-like abilities of the same spell level, choose randomly from among them to determine which one is stored in the bloodstone. The bloodstone can only store racial spell-like abilities that emulate a spell, including altered spells, like invisibility (self only), but not unique spell-like abilities possessed by the creature. Abilities with altered effects are still altered, so a creature activating the bloodstone for greater teleport (self only) would affect only itself and a bloodstone storing summon monster II (Small fire elemental only) would still only be able to summon a Small fire elemental. Additionally, the bloodstone can’t store spell-like abilities that duplicate spells with expensive components costing more than 250 gp.
The save DC, caster level, and other attributes of this ability remain the same as when the creature was still alive, though the creature who activates the bloodstone can choose the targets, area, or shape of the spell, and make other decisions, such as controlling the target of dominate person. The bloodstone can take any actions necessary to manipulate aspects of the spell, concentrating on the spell, redirecting the spell, and so on, up to a full normal round’s worth of actions.
If the sacrificed creature doesn’t die during the casting of the spell (for instance if it was merely a summoned creature) or is brought back to life before the spell’s duration expires, the bloodstone loses its magical power. The fragment of the creature’s spirit trapped in the bloodstone does not hinder attempts to restore the creature to life.
My Question: what's the point of the duration?
It doesn't say that the bloodstone disappears when the spell is over and you have to kill the target by the end of the 10 minute casting time. Am I missing something?