A few things I haven't seen mentioned yet.
Blood Magic
Drain life instead of mana, giving you one less thing to worry about. You'll almost always worry about your hp anyway.
- Works when you want to put a bit of points into constitution
- a powerful heal and a chance to control an elite monster while clearing his minions.
- Incredible crowd control in the form of Blood Wound
Disables
A full set of disables guarantees that even the hardest bosses will be frozen in place for more than half of the time of the battle. This helps a lot at harder difficulties and makes going through normal and easy a cinch.
From other posts:
- Winter's Grasp - quick cast slow
- Cone of Cold - Before it was fixed this was ridiculously broken and won the whole game for me on my first playthrough literally. Post-patch this is pretty balanced and yet still manages to hold down virtually anything, even bosses albeit for a shorter period.
- Crushing Prison - quick cast disable (works pretty well with grasp)
- Mind Blast - when things get out of hand and you find yourself surrounded
- Sleep - great for every kind of setup, even as preparation for mass paralysis.
- Paralysis - A more reliable form of disable, and from my experience, seems to have a higher chance of success against elites and bosses.
- Mass Paralysis - Massive version of paralysis (relied on this A LOT after cone of cold nerf), and yes, still useful against bosses when every other spell is on cd. If you've got another mage, this is a great setup for massive spells, even better than sleep since they won't be able to move even after damage. (Prefer this over waking nightmare most of the time)
- Blood Wound - for every creature with blood, this is the best form of disable a mage can get as it also does considerable damage.
I managed to use this uring my awakening playthrough, and here I used two mages.
- Mage 1 casts paralysis, mage 2 prepares a blizzard
- Blizzard is cast: Mage 1 casts Tempest with Spell Might(Storm of the Century), Mage 2 casts Inferno
All this can also be done with just one mage (except for inferno as it's hard to get any more points there with all the other trees filled up)
That clears just about any mob leaving Nathaniel, a few crushing prisons and grasps to take care of stragglers and if any get too close, there's always a cone of cold waiting for them.