As a solo 350 lvl Wiz I am doing less damage on the same mobs/dungeon than I was doing at less than 200 lvls… It might have started after the last big update not sure, now I am losing interest in the game because of this. I'm GM in all magics my mass hold is almost always partial now and doesn't last as long and my multistar attack much less than should be…
Is your meditation level 5? This will help with Hold Duration.
At level 350 (actually at the Level you can wear Pro Gear) I suggest focusing your Damage Spells away from Multi-Blade.
Try to get Pro Elemental Gear then try out Electric Fury/Cold Snap/Earthquake/Gust of Wind/Sand Storm. Once fully geared in Pro-Elem Gear you should be doing more Damage than your Multi-Blade ever did.
I will certainly try that Wolf, thanks
One thing I would also recommend checking is that every mob has different resistances to certain types of magic. If you "Look" at the monster before you start the fight you can see what resistances they have.