A skill belonging to Caster of “Red,” Shakespeare. It could also be called “Literary Masterpiece Endowment.” It consists of making a passionate poem that begins with the following preface: “I will now explain this person's amazingness in minute detail, so please listen without thinking it tedious, everyone.” It can raise the sharpness of a blade by saying “it can cut all things” and increase the sturdiness of the blade by saying “it can receive all attacks,” but either way, it requires literary expression great enough to move the readers in order for it to take effect.
For writers who have left their names in history, there is a good chance that they will possess such a skill or Noble Phantasm.
For Shakespeare with his extraordinary fame, he can produce even Noble Phantasms of C~E rank. For making an E rank Noble Phantasm, it would be at the level of turning a pebble lying anywhere on the road into a Noble Phantasm. For D rank, it would be a mass-producible manufactured item like a modern weapon. To reach C rank, it needs to be weapon with sufficient spiritual status for a literary master like him to express.
In this war, he used Enchant on “Miike Tenta Mitsuyo,” a famous sword said to have been the favorite blade of a certain one-eyed great swordsman. Naturally, it is C rank.

Fate/Apocrypha material: Fate/Apocrypha Encylopedia