Cay was called by her diamond to tell the future

Blue Diamond (Tilly): "Cay, tell me what's going to happen when the rebels come?"

Cay: "I foresee the rebels attacking the cloud arena, they will destroy the physical forms of seven gems, including two of my ruby guards and myself. Immediately after my form is destroyed, the rebels with be captured."

Blue Daimond (Tilly): "thank you, that's all what I needed to hear."

Cay walk back to her ruby guards