Versatile Mage: Summon Death, Summon Holy Grail War

I traveled across the entire French world and became a victim of the summoning system. Everyone thought that my dimensional channel was connected to some terrifying demon emperor. Only I know that I can't summon the demon at all. Because my dimensional passage leads to the Seat of Heroic Spirits! While other mages were still complacent about a warrior-level demon, I looked at the Holy Grail in my hand and fell into deep thought. There are no magicians, no clock towers, and no so-called Royal Family in this world. So... When the Holy Grail arrives, the Command Seal emerges. Who will be the master? Who will be the heroic spirit? The answer is simple. I, alone, am the seven-in-one Great Master! "Saber, go and let Salan see what an anti-army weapon is." "Archer, that emperor-level demon is too noisy, use your deviant sword to shut him up." "Caster, make it rain on Bo City. Remember to use the Godly Rune." This Holy Grail War that swept the world was just my one-man show from the beginning!