So we had an interesting question come up in game tonight. When an invisible creature is in the 10 foot radius of an invisibility sphere is it made visible to the others inside the sphere.
The question mainly comes up from the part of the description that states "Those affected by this spell can see each other and themselves as if unaffected by the spell"
So my question is does Invisibility Sphere overpower the lower level spell? Is the invisible creature invisible twice? Is the invisibility effectively purged for those inside the sphere?
The two spells overlap, and do not stack (yes, technically you will be invisible twice), but there is almost always an unspoken "barring other circumstances" in spell descriptions. In this case, an invisible creature who is in the area for an invisibility sphere would normally be visible to other affected creatures, but he is still invisible, so they can't see him.