Improved Soulspark Familiar (3.5e Feat)
From D&D Wiki
Improved Soulspark Familiar [Incarnum]
Your ability to shape incarnum into a creature known as a soulspark has become more powerful.
Prerequisite: Ability to shape the soulspark familiar soulmeld MoI
Benefit: From now on, the essentia capacity of your soulspark familiar soulmeld is 2 points higher than normal. In addition, whenever you invest essentia into this soulmeld, it gains two abilities, instead of one.