So it seems having a fever and lots of free time and playing various RPGs leads to some interesting ideas. All of these are defensive spell ideas that can be tweaked obviously for balance.
Fire Wall: A barrier that halves damage received and causes some damage to enemies when they attack. The affect is reduced by 50% when a water spell hits it and if it is hit again it vanishes. Has a cool down.
Earth Barrier: Greatly raises defense and damage taken is lowered, but can only be used on one party member and has a cool down. Can be pierced by lightning based spells.
Water Shield: Covers one party member and is purely defensive. Has a cool down and can be pierced by lightning spells and the effect is greatly reduced by fire spells, though it nullifies all damage from fire. Lasts for 2 fire spells or until time runs out like the rest.
Ice Barrier: Similar to water but is significantly weaker to fire. Meant to be the first spell of the series you get before upgrading to water.
Wind Barrier: Weak to Earth and makes fire attacks stronger, but greatly injures all enemies attacking and can only be stopped by the time limit placed on it.
Lightning Barrier: Similar to Wind but can be stopped by 2-4 Earth spells.
Can probably think of more elements if I knew how in depth magic is gonna be. Basically this is all I got for now if mages do become a thing, considering there are spell users in game it makes sense though.