Blank Spell Arrow (VH)

Enchantment 
This enchantment creates a spell arrow with no spell stored. Instead, any spellcaster may, at a later date, place a spell in the blank spell arrow, and then use it as if it were a normal spell arrow. 
Blank spell arrows have a capacity, representing the energy cost of the largest spell they can hold. When a spellcaster wishes to use the arrow, he casts the spell normally, but directs it into the arrow. If the spell is too big for the arrow, it is wasted. After the arrow has been filled, it must be used within one day (by the spellcaster or someone else), or the spell dissipates harmlessly, making the arrow blank again. 
All other rules for spell arrows also apply to blank spell arrows, with one exception. If the caster of the spell is also the archer, he can determine its effect at firing time, and maintain it normally. (He cannot put more or less casting energy into the spell at firing; casting energy must be in the arrow.)

Energy cost to cast: 30 times the desired capacity. The Spell Arrow rules for non-arrow missiles apply to Blank Spell Arrow as well. 
Prerequisite: Spell Arrow.