Gilgamesh x oc fight for the grail

Basically in this story So dacha summoned Gilgamesh for one reason and one reason only. Just so she'd be able to fight in it, she didn't need a servant she thought she already strong and able to fend for yourself so basically Gilgamesh is just there for show. She had no use for him and he had no use for yher. That is until both of them fall for one another.