When a Wither Became Hassan in Type-Moon

He was originally a Wither summoned from Hell, but for some reason, he transmigrated.

The Holy Grail War is actually this complicated?

This seems like such a hassle!

The other side is full of powerful fighters, but what about our side?

A dual-wielding assassin, an assassin skilled in magic, an assassin who gangs up on people with clones... Is there even a normal assassin here?

(Newbie's amateur work, please be understanding.)