Wizards are EXTREMELY squishy. When you run any dungeons corresponds to your level (party or Hard mode), most likely you will experience dying in in a couple of hits, regardless if you have a bard or not! (Unless you have all +20, That can make any class un-squishy)
What you need to do as wizards is to kite around the monsters, avoiding getting hit. The best thing about being a wizard is its ranged skills. With aura kingdom's mechanics that enable players to jump+cast skills, combining with Nocturnal weapons (will be mentioned later), it makes ranged dps class such as wizard much easier to survive in dungeons than other classes.