For the missiles, you can change it under "Combat - Attack - Weapon Type"
There is :
- Normal - This is for melee attacks, like a knight or crypt lord.
- Instant - This fires a ranged attack that hits instantly, like the rifleman
- Artillery - This fires an arcing artillery missle, that hits the area that it fired at. The damage is dealt at the given area with an AOE effect (e.g. meat wagon, mortar team)
- Artillery (Line) - This fires a straight-firing artillery missle, that deals damage in the line of fire that it targets (e.g. ballista (as was used in reign of chaos))
- Missile - This fires a ranged projectile that travels on the designated arc and speed, and deals damage to the target unit when it hits. unlike artillery, it doesnt miss if the unit moves (homing enabled/disabled changes the projectile to curve or not) (e.g. preist, archer)
- Missle (Splash) - this fires a ranged projectile that travels and hits the ranged unit, like the regular missle; the only difference is that it deals AOE damage to units around that unit upon striking (e.g. frost wyrm)
- Missile (bounce) - This fires a ranged projectile that hits the target unit, then bounces to another enemy unit if within range (e.g. huntress)
- Missile (Line) - THis fires a missle that deals damage to units in its line of fire. Unlike the lined artillery, you can enable it to be homing. I cant realy think of an example for this one.
For the increasing/decreasing attack/damage, you can either add item abilities, or substitute units (not recommended since its really buggy).