The Protean Scourge from the MM3 casts spells as an 8th level Sorcerer, and many of the stock spells are of a buffing nature (Mage Armor, Mirror Image, etc).
It also has an interesting ability to split in two:
Split (Su): When damaged, a protean scourge splits into two identical versions of itself. This ability is not an illusion; each new protean scourge is fully capable of dealing real damage and poses a real threat. Each version of the protean scourge has all the current statistics and access to all the current abilities of a single creature, including any remaining uncast spells. However, any spells cast by either split protean scourge come from the total pool of remaining available spells. So, the two versions share access to remaining spells; each does not get its own spell list or spells per day. Neither half of the protean scourge can change shape as long as the creature remains split.
Each version has the protean scourge’s current hit point total (they do not split remaining hit points), and both versions of the protean scourge must be slain to kill the creature.
The split protean scourges can recombine into a single creature in a process that takes 1 minute. While it recombines, the protean scourge is helpless.
What happens if the protean scourge is buffed with Mage Armor, Mirror Image, Displacement, or the like, prior to its split? I'm assuming the bold portion above means it gets "double" the effect for a spell cast before the split?
Secondary question: A split protean scourge has Mirror Image cast on both its halves. If both halves are standing next to each other, should the random roll include all images, and both halves? They would all look the same, after all.
