Sphere Taker (3.5e Feat)
From D&D Wiki
Sphere Taker [Fiend]
Take a Sphere from the Tome of Fiends' Fiendish Spheres.
Prerequisite: One of the following: Caster level 1+ from an Arcane Spellcasting Class (Spontaneous or otherwise), qualify for fiendish feats, or already have access to a fiendish sphere.
Benefit: Gain a basic, advanced, or expert access to a Fiendish Sphere.
Normal: Can only gain spheres from Attune Sphere feat or some other fiendish source otherwise.
Special: This feat may be taken multiple times and acts as indicated in the Fiendish Spheres section of the Tome of Fiends.