I hear the next spell element is going to be "Cactus". This is an interesting idea and I want to share some potential spell ideas for this element, whether they would be taken directly or be used as inspiration.
Roller:
A mobility/offense spell. On use, the player character curls up into a cute ball and grows some spikes. They roll in the direction they were travelling and retain their momentum, with slight turning control, damaging enemies they ram into. During this roll, any elemental effect on the ground or on an enemy that the player hits is stuck to the player. When the roll ends, there will be an explosion from the player of each elemental effect the player grabbed while rolling.
This roll would also get dynamites stuck to it because that would open up some really funny teamplay possibilities of rolling into a horde of enemies with a dynamite stuck on you, or as a solo throwing a dynamite in front of you before using the spell.
Roller concept 2:
An alternative concept to Roller, sends out a cactus ball in the direction the player is looking that sticks elements (and potentially enemies this time) onto it. This roller can be redirected by shooting or hitting it in the direction you want it to go. A player can stand on top of and ride this roller for mobility. It could have the same element explosion effect as concept 1 when it expires. Potentially, Elec's "Strikes" spell multiplies the roller.
Trap:
Apparently one of the cactus spells will be a turret. I think a trap spell could go along nicely with this defensive setup playstyle. This spell sets up a prickly cactus trap where it lands, which will linger with a relatively large hitbox and trap nearby enemies for a short time when triggered.
When the trap is shot or hit by a player, it will explode in a burst of non-piercing spikes that damage and slow or stagger nearby enemies.
When it is destroyed with an element, the spikes adopt that element.
Potentially, Elec's "Strikes" spell multiplies the trap.