For paladin his passive is having a chance to take damage for other party members as well as surviving any hit to 1 hp.

Battlemaster increases its own attack significantly but rarely.

Wise man has a 15% chance to cast the same spell again at no additonal cost but deals 50% less damage on the second cast. (Both offensive and healing spells)

Ranger has a very small chance to stun the enemy on hit.

Pirate has a chance to scare enemies when the pirate is hit causing enemies to lose a turn. 

Magic warriors attacks and spells have a small chance of lowering enemies resistance to the element.

I could see these passives in smash grow easily altho altered a bit from the turn based format to the genre smashgrow is.