Right so here's the starting out guide.

1. Make your character, pick both mage like options at the start.
2. Pick the ring of reaction in the second area.
3. Progress through until you get the life rune.
4. Enchant your weapons and armor with life rune and sell them when they're at 1 durability.
5. Progress until you get the void rune.
6. After getting the void rune and if you have 8 mp available, go to the arena. Select the 1st hard arena(Maybe others too, idk since I haven't tested it on them yet)

Run into an unoccupied corner if there is one, then use the spell life, life, life, void, spell. It'll summon 3 minions for 8 mp instead of 1 for 6. Summon all 3 next to yourself blocking you into a corner. AI doesn't attack your summons ever so you should be completely safe, and you can take swings at the mobs as they walk next to your summons. Summons also never run out, so no need to worry about time. If all corners are occupied, you'll need to use another triple summon spell to surround yourself.



Things this doesn't work on because def is too high that I've seen so far.

Basilisks
Devourer

Things I've tested so far that they could kill

Bugbear
Trolls
Giant Spiders

Then you're on your own since I haven't done much else or tested vs other mobs. :P