I think best to change way potions works now . Heal spell should replace potions and that spell have 20 seconds and no mana cost for that spell . This is a general spell for all classes.
Belt regard of potion length 3 - 6 spaces and each potions correspond to 1-6 number key’s to activate certain buff potion or debuff with location selection.
Potion for buff ideas : Speed potion (Increase user movement and attack speed by 40 % for 10s, and can have suffixes max 2) , Regeneration aura potion (allies and caster get’s regeneration of health 25 hp/s for 10s + 2 suffixes) , Dodge potion (Increase user dodge rating by + 50% more for 10s + suffixes), Armor potion (Increase user armor by 50% more for 10s).
Potion for debuff (Potion act like a grenade here): Weaken armor ( Enemies receives - 25% less armor mitigation for 10s + 2 suffixes) , Slow ( Enemies attack and movement speed reduced by 25% for 10s + 2 suffixes).
This gives some extra fun and that should be available only in endgame.