I don't believe anything like these exists. I call them "hidden" spells- their symbol is a question mark. When casted, they hang over enemies like negative wards and stay there until they attack you, the caster. Once they do this, it unleashes whatever damage or affects it causes. These can be used to make enemies waste turns trying to remove them, or make them avoid attacking you... here are some ideas for each school.
Overlying Smoke: when activated, -90% smokescreen
Electric Piranhas: when activated, deals a set high amount of damage
Icicle Spears: when activated, deals a low amount of damage and freezes enemy for one round
Spiky Cactus: when activated, deals x amount of damage per pip when it was casted Gray Goo: when casted, ensnare (like a stun, but not effected by block/immune) for two rounds
Snake Trap: when activated, deals x amount per pip over three rounds
Flaming Skulls: when activated, steals a set amount of damage
Booby Trap: when activated, destroys all enemies positive charms (possibly shields)
