What would your special unit be able to do?

[TheGreatErenan]

What about a unit that can turn enemy units to stone? The petrified unit would remain on the map as an impassable and vision-blocking obstacle to both teams until destroyed (the unit would retain its HP, I guess, and would take damage from any other unit as normal). Presumably petrifying a unit would give a +1 wit bonus to the player performing the petrification.