I started my first crowd control pale master and have gotten him to level 18, but seem to having troubles with the end game content (amrath, path of inspiration namely).

What are some good strategies for a wizard to use against RED named monsters with a lot of hit points? Most content before this I could easily just use insta death or just spam scorching ray. Now monsters have much more hp and I seem to have hit a wall. Since I'm fairly new to playing casters, I really only thought of using energy drain along with some simple debuffs, but have no idea on any offensive spells that would work well. I hope this makes sense.

Any thoughts? Thanks!