(Humanized.)

Thunderstorm was happy and lovable, until something weird happens. He walks into Ponyville but he doesn't seem friendly, Pinkie (as always) throws him a party, everyone comes, but he wasn't happy. He throws a big scene breaking Pinkies heart and angering the town, but she's determined to change him.

I write better if it's humanized, just to clarify. Thanks for reading, I spent all my time on this, so if you have any constructive criticism, you can, just be nice about it.