Did anyone get a feeling of the water running through the Source might be the same water in the Temple's spring? I thought of that automatically. and then when I saw MIB drown in the water after being attacked by jacob, it made me think of how characters (Sayid) drowned in the Temple's spring when they were close to death. Which further makes sense to me that MIB became "claimed" by evil as anyone else who was saved in the Spring. This event is what turned MIB to evil, and over hundreds of years allowed evil to spread inside him to what he has become in the present.
I dont know, it may be far fetched idea but i definitely saw the connection right away so i thought it was worth mentioning