I figured out one of the spells I can cast is “Summon Monster”, although I could have the name wrong. It is kind of fun to use, walk into the first level of the Abyss where there are a few monsters and cast the spell. He shows up, walks around and starts killing everything he sees. Unfortunately, about half the time he shows up and faces me and doesn’t see the monsters near me. I tried hiding around a corner and he came to me instead of going after the monster. Other times when I’m facing him and switch to my sword and it automatically swings, killing him in one blow. I also found he is useless against the shadow monsters, they one-shot him.
You’re only going to get so much out of a 1st-level summoning spell, because, well, first level.
That said, there’s a hint there about other spells you can make.