Summoning Ritual

Reveal the top X cards of your library. You may put a Servant creature card from among them onto the battlefield. Put the rest either on the bottom of your library in any order, or into your graveyard.
"I announce! Thy body shall be under my command,
my fate shall be determined by thy sword! Follow the call of the Holy Grail. If thou wouldst obey this mind and this reason, obey me! Then I shall entrust my fate to your sword...!" - Rin Tohsaka