[@Slime] Oh I have no idea. That's entirely up to you in the end. The lists I provided have some really decent gunpowder servants. Or you can take your own figure from history.

As you can see, each of are choosing servants to a particular play style. Roland is mostly a defensive Servant, while Sun Wukong uses his many tricks to engage the enemy, and the Pheonix just destroys everything it touches. You need to find a servant whose story will work best for what you want.