Here are a few "Gun" type spells that i wiped up from the surprisingly fun game Ratchet and Clank: Up your arsenal. I had planned to do 10 guns but ended up doing only 6. All spells can be used by multiple heroes.
Shock Blaster - Fires 9 bolts of energy, slows and the bolts jump in later levels (units can dodge the attack if they stand in the small area between the blasts).
Agents of Doom - Robots follow around and will attack until they run out of ammo then explode (thanks to Vexorian and TheJ89 for their resources that i added in this spell)
N60 Storm - Fires bullets forward that damage the first unit they hit, bolts jump in later levels
Suck Cannon - Sucks up a unit in a box, then when cast on another unit the box will damage and stun, sets units on fire in later levels.
HoloShield - Creates a shield that draws enemy attention, shocks and counters in later levels.
Annihilator - Fires a missile that damages the first unit(s) it hits, Mines and missiles will pour out of the explosion in later levels.
If you don’t like the skill set up or just want to use one, just convert the skill back to a hero one along with the data of the skill (level 1 dose nothing in all skills). Then get rid of the “V0.0 do nothing” part of the trigger and reset the level checks in the trigger for the right level.
5/5 you rock, who cares if they aren't orginal THEY OWN! 
