Title.
Right now, there are plenty of neat interactions in the game. Lightning can conduct and supercharge Iron/Gold blasts, poison can block out light spells, and sand can even create indestructable glass walls upon colliding with lightning.
Sand has one property, which is the sand piles it leaves behind. Unfortunately, these sand piles are rather pointless and only serve to lag the server.
So, what if we gave them a purpose?
Introducing, Dust devils!
Upon directly hitting a sand pile with a wind spell, it could form into a dust devil that goes in the direction that you fired the attack.
The actual effect of the dust-devil would be decided upon by development, but some realistic ideas would be for it to proc the blindness effect from sand, knock players around like a tornado, or just do some damage equivalent to that of the wind attack.
Why add this?
Sand is meant to be a magic that empowers other magic. In exchange for that, it has extremely average stats. Giving it a fun interaction like this sticks to what sand magic is all about, and implements another fun magic synergy into the game.