Hi, Craig234
I'm new to this game just like you. I've been playing for a few weeks and I've been experimenting with some skills. I have to agree with Cleglaw angd the others. Hellspike is nasty! My level 43 mage has Hellspike lvl 5. She can kill everything in seconds including bosses. I think you should also train Freeze. Just Freeze the monster then hellspike like crazy. If you can click fast enough, you'll send out lots of spikes in a second. Even Josephina falls rather quickly!
Some people also suggest the use of such spells as Elememntal Hail or Elemental Strike. I found those two skills less powerful compared to Hellspikes. On the other hand, Divine Death is very powerful. But you have to go through the blessing ritual first to get that reward.
In the end , though, it's your choice as this game gets a lot easier late game. Btw, Hellpikes work effectively on easy and normal modes. I don't know about hard mode. Not sure if I want to try.