Artoria

The Holy Grail war has started, so you make a ritual. You make a special summoning circle with a catalyst. The Holy Grail facilitates the process by providing the necessary magical energy. now you start to pour mana into the special summoning circle, which it starts to shine, then a bright giant flash of light bursts, and then at that moment, you summon your servant Artoria. You did the ritual all in your room at that moment your command seals appeared on the back of your right hand