How was Sundar at the time you joined? According to Wikipedia he spearheaded the development of Chrome, GDrive, GMaps, GMail and the VP8 format which are all monumental products so he sounds like he was quite like every other talented hacker that thrived in early Google culture. Is that not the case? What made him turn to the dark side so abruptly?
Sundar wasn't a hacker, he was a product manager, and he was very good at identifying growing products, becoming their leader, and riding them to glory. But what really sealed the deal was Sundar's ability to sit in meeting with Larry Page while all the Chief Lieutenants fought, and patiently argue them all down (which Larry never wanted to do).
It's news to me that Sundar had anything to do with gdrive, gmaps, and gmail, except that he was head of Apps for a while, long after those products had completely established themselves.