By expending multiple lower level spells, you can fuel a single, higher level spell.
Benefit: You can expend multiple spell slots or prepared spells to power a single, higher-level spell. The combined spell slots or prepared spells expended must equal or exceed the level of the higher-level spell you wish to cast. Any unused spell level energy is wasted.
This allows you to cast an additional prepared or known spell of that higher level, even if you have exhausted your spells per day for that spell level. It does not allow you to cast a spell of a level you cannot normally cast. Casting a spell in this way requires more time than a regular spell. If the higher level spell’s normal casting time is a standard action, the siphoned spell instead takes a full-round action to cast. A siphoned spell with a longer casting time requires an additional full-round action to cast.
New Paths: The Expanded White Necromancer Copyright 2013, Open Design LLC.; Author: Marc Radle.