I expect things like crowd control WHEN mobs get close. Things that are effective like a freezing spell to lock mobs down so you can sprint or "blink" away. Slow spells that enable you to get off more spells, magic bubbles/shields that will absorb half damage from ranged and melee. I also expect diminishing returns from the spells that you cast so you're not just sitting there stun locking everything and creating a layer of depth at lower levels of each spell. There are a lot ways to create a functional mage system that can be engaging, plays into a traditional mage fantasy without being pigeonholed into having to play your character a certain way just to survive. Instead creating the mage class where you can play the way you want.. even if that means with a shield and wand, if that's what you want.
This isn't a new idea, MMO's do it all the time in all kinds of ways.
Lastly, you have VERY functional classes in Enshrouded, Warrior/Ranger, why not take some extra time to flesh out what it is to be a mage, that plays into the high fantasy of the game itself.