Fragments (Steven Universe Future)

It was directed by Kat Morris, Alonso Ramirez Ramos and Liz Artinian and written and storyboarded by Lamar Abrams and Miki Brewster.

During training, she makes him climb a mountain while carrying boulders and then try to shatter them, sleep outside, run very fast, and pick up fish directly in a pond.

Distressed, Steven, now back to normal, quickly returns home and goes into the bathroom, ignoring the concerned Crystal Gems.

[1] The episode was favorably received by critics, who praised Zach Callison’s voice performance and the darkness of Steven's transformation from a happy-go-lucky kid to the scarily powerful being.

Shamus Kelly of Den of Geek praised the episode's darkness and Steven's arc leading him to a full breakdown.