Flash Sentry.

Musician, nice guy, potentially decent boyfriend, highly lacking in personality otherwise.

This kind of description would make anybody feel sorry for the guy, but none were more upset than Pinkie Pie, who was greatly upset by the idea of someone with little personality.

But then, once she sees him taking out a book for "young adults," she's elated at the hint that he may have some hidden traits or quirks after all!

Now all she has to do is get the book and find out what's it about.

Easy, right?