Attacks are partially implemented along with the enemy AI. When magic is used during combat in the original Ultima V, the screen inverts in stages (see a screenshot of moongate travel) along with an eerie sound. And if it is a projectile (like the Magic Missile), then you will also see the projectile animation.
BTW: nice avatar xlibman.
"The enemy begins to fight back"
"They are ganging up on me. RUN!"