Hi,
I just started this game and playing a pure Wizard (C2). I got with lvl 20 into the Crystal mines…I’m going very fast oom.
In the Quest-Bossfights I get to use some attacks and then going to autoattack it for 10 minutes because I’m oom…
Is this intended or am I doing something totally wrong??
Looking forward to get some help 
Technically you aren’t doing anything wrong.
Boss fights are known to be slow, easy, slow and tedious. (And slow.)
Wizards definitely have some mana problems in the early game, especially Wizard C2. But there are a few things you can do to maintain your mana longer.
Buy mana potions. I know they are really expensive, but it beats auto attacking for 10 minutes.
Save EXP-cards to boss fights, then use them to level up. This will instantly heal you to full hp and mana, which is reeeally useful.
You can put up and use campfires even in boss battles. This may not always be more effective than auto attacking, but it’s worth a try.
Get equipments/gems which increases your max mana and mana regeneration.
Ok…so at least I know Im doing nothing wrong 
Thanks for the advices!!!
Seems you choose the hardest part for leveling a wizard lol
pretty sure wizard c2/c3 are currently the hardest things to lvl.