How come the Ace of Cups isn't considered the Holy Grail?

【Welcome to the world of Yu-Gi-Oh! Pigeon. 】
In this world, the Creator Dragon, awakening from a long slumber, has caused all sorts of chaotic changes to the world. As an alchemist, you will travel the world in search of a way to save it.
During your journey, you will rely on the temporarily borrowed powers of past Duel Kings to collect materials, and transform them into cards through alchemy. Ultimately, you will build your own deck, defeat the Creator Dragon in the final duel, and save the world!
You Du: "Then the question is, what do you mean by sending me to the Type-Moon World to participate in the Holy Grail War?"
Although the system is based on the game background, it gives him the alchemy that can use various materials to create Yu-Gi-Oh cards.
But he is just an ordinary card player who is powerless. How can he compete with those hangers-on who are sweeping the floor with their light cannons?
Of course, he would change his job to a summoner on the spot, directly summoning duel monsters to surround and beat up the opponent, while using various magic traps to deal crazy damage!
By the way, you just summoned a total of five skeleton soldiers, right?
Wu——!
Meteorite is coming!