If you could add a sixth element...

I actually kinda think that if there were to be a change, thematically it would make more sense to remove thunder
Air is already an element, they're somewhat closely related
And dexterity is more or less useless so it wouldn't make a huge difference

 

the element of surprise

 

We currently have the following skills:
Strength -> Earth
Dexterity -> Thunder
Intelligence -> Water
Defense -> Fire
Agility -> Air

Skills that might work?
Vitality -> Life
Luck -> Cosmic

 

Element of walls (increases your stats while in Fruma)

 

Wisdom - Light

Points added to Wis increase your base mana regen.

The wisdom item pool would steal a lot of things from modern intelligence, but this would create two different approaches to mana, completing the symmetry of the skills.

Int would come first in the ETWLFA matrix, and int items would be spell damage related, while Wis would be on the defensive side and focus more on mana sustain.

Active powder special is Surge, a miniature mana pot - mana regen inflates to like 300/5s for a short period of time.

Armor special is Inspiration, which gives you a Light damage bonus for every point of mana you regen.

Anyway this would probably break wynn as-is but conceptually I think it's neat.