Steven Universe - She did what she did to avenge Pink Diamond

It was easy to think of Jasper as "The Bad Guy" when we all thought she was just an Imperialist thug on Yellow Diamond's payroll. But now we know that her motive was avenging Pink Diamond… She only did what any of the Crystal Gems would have done in her place, because she loved Pink Diamond as much as they loved Rose Quartz.

The people who were hoping for "Jasper's Redemption" had it backwards. In Jasper's eyes it was Rose/Steven who needed to "Redeem" themselves. Steven needs to find a way to make things right with Pink Diamond, it's the only way he can help Jasper now.

Something that made her take a very hardline stance against shattering gems later on, enough so that she was willing to seal away one of her own. Something that made her want a weapon that could destroy the physical form, but never the gem itself.