saber armor

Saber's fighting spirit boiled as well, and exploded. The prana surge enveloped the girl's slender dark suit in a swirl like a tornado― and the next instant, her body was wrapped in a silver and azure armor. The armor and gauntlets created as by magic was the true form of the beautiful King of Knights, as a Heroic Spirit.

"Saber..."

Swallowing nervously, Irisviel called from behind. She could feel the fighting spirit released by both Servants, as well as the atmosphere strained by that tension. ―There was no room to disrupt this battle.

- Fate/Zero: Act 3, Part 3