Long version: It's revealed that the protagonist isn't a digital avatar of a mage like the other Masters. He's a sentient AI, based on some comatose person in the real world. Anyway, after the protagonist wins the War, he/she seals MOONCELL preventing anymore Holy Grail Wars. He/she then says goodbye to his/her servant and to Rin then the automated system deletes(i.e. kills) him/her afterwards. The last shot during the credits shows Rin in the real world (where she is blonde) getting a text message from the protagonist, revealing the location of his/her "real" self. Rin vows to find him/her.