Sentient Manifest Mind

Through practice and fine tuning of the magic used to awaken the Wizard's spellbook, they manage to have given it its own conscience.

The spellbook gains the ability to speak telepathically with their caster; even without the manifest mind summoned. It cannot see and is thus unaware of its surroundings without the Manifest Mind summoned. 

While the Manifest Mind is summoned, it is capable of speaking to those around it in any language known by its caster.

The spellbook, and its manifestation, shares the ability scores and alignment of the caster, but has its own mind and capable of having its own desires. The spellbook may attempt to get the caster to act on their desires but is not capable of acting on their own without the command of the caster to do so.