In the past year or so, I've been busy building a casual turn based card/board game myself, and as it turns out, I've built quite an impressive list of abilities already. I'll try to go through it and see if I can modify anything to make it suitable for a fantasy setting.
Some are obvious abilities, some are a little bit more complex.
Healing Abilities:
Regenerate X: This unit heals X hit points per turn (in combat).
Defensive abilities:
Auto-Retaliate: Always retaliates, and is capable of retaliating in any direction.
I built this one to give certain units the ability to ignore flanking rules, like multi-barreled cannons.
Needless to say, under my flanking rules, units can not retaliate to flanking attacks.
Evasive Manoeuvre: Exhaust to evade the next attack aimed at this unit. Cannot retaliate while evading.
Protector: Exhaust to have this unit take damage instead of an adjacent unit.
Super Protector: Exhaust to have this unit take damage instead of another unit in movement range of this unit.
Hyper Protector: Exhaust to have this unit take damage instead of another unit.
The protector abilities serve to make tanking units more valuable. It's obvious the more powerful the ability, the less units actually have it.
Given AOW's combat system, only the basic protector ability and giving it an automatic trigger would probably work.
Heavy Armor: Has double defense while protecting.
Shield X: Prevent the first X damage dealt to this unit each turn.
Energy Shield X: Prevent the first X damage dealth to this unit each attack.
Movement abilities: (These move your unit to other tiles when activated, and enhance movement when passive)
Defensive Manoeuvre: Exhaust this unit to move it a tile back while attacking. Uses all movement.
Basically, this order makes a unit have only a single attack this round, and move only one tile, but it cannot be retaliated against.
Also note that in my game, moving back cost 4x as much movement points as normal movement did, so most units would take more than a single turn to move a tile back to begin with.
Super Mobility: This unit can move in any direction without turning. Turning still consumes movement points as normal.
Haste: This unit has double movement on the first turn.
Charge Dash: This unit can deal area damage 0-X around itself, where X is its damage value modified by the number of tiles moved. (More tiles moved equals more damage done)
This ability has 3 turns cooldown.
Quick Turn: This unit no longer expends movement points to turn.
High Boost X: Exhaust to move this unit X tiles in any direction in a straight line. Cannot attack this turn.
Attack:
Duel: Target unit can only attack this unit next turn.
Taunt: All adjacent enemy units must attack this unit next turn.
Dual Wield: Can equip a weapon in both hands.
Ambidexterity: Can equip any item in both hands.
Blade Aptitude X: Deals X more damage with melee weapons.
Ranged Aptitude X: Deals X more damage with ranged weapons as long as the target is 3 or more tiles removed from this unit.
Instant Attack: Perform a single attack that cannot be dodged or blocked.
Corrosive X: Attacks made by this unit remove X defense from the target for 1 turn.
System Shock: Convert all impact damage to unpreventable non-elemental damage on the afflicted unit(s).
(Damage in my game is dealt as a part normal damage, and a part impact damage. Impact damage is cannot kill a unit and is removed the next turn. So it's virtual damage until a unit with system shock scores a hit in the same turn.)
Piercing: This unit also hits the tile behind its target.
Custom Projectile X: Creates a missile weapon on a tile adjacent to this unit. The weapon has X movement, 1HP, and flying. The missile deals full weapon damage when it moves into the same tile as any other unit and is destroyed when it does.
Basically, it makes small controllable missiles which can be gunned down with ease (They don't have any defense), but are very dangerous for melee units.
Double Impact: Deal double impact damage to units standing between this unit and any object. (Like a wall)
Highly situational, but works surprisingly well in a System Shock build.
Status attacks:
Frost Attack X: Attacks made with this weapon Freeze the enemy for X turns.
Stun Attack X: Attacks made with this weapon exhaust and stun the enemy for X turns.
Stagger Attack X: Attacks made with this weapon stagger the enemy for X turns.
Blinding Attack X: Attacks made with this weapon blind the enemy for X turns.
Heat Attack X: Attacks made with this weapon make the target take 1 damage each turn for X turns.
No Retaliate: Targets do not retaliate in response to attacks made by this unit.
Knockback X: Knocks the target X tiles back.
Charge X: Exhaust to add a charge counter to this unit. This unit has a maximum capacity of X charge counters. When you attack, remove all charge counters and multiply your damage and impact damage with the number of counters+1 removed.
Skipping turns to build that one massive attack to decimate that big guy over there? Small defensive units love this one.
Mortar Shot: This unit makes an attack with +50% range rounded down but loses 50% damage rounded down. Ignores obstables.
Stealth: Cannot protect against this machine. Attacks made by this machine always count as flanking attacks.
Negative Effects:
Pacifist: This unit cannot attack.
(Often seen on healers)
Weakness (Already exists in AOW)
(Element) Deathblow: This unit instantly dies to attacks made by the named element.
The penalty is probably too steep for AOW since resurrection isn't as common in this game.
Blindness: Affected unit cannot attack.
Stagger: Affected unit takes double impact damage.
Stunned: Affected unit cannot take another turn.
Burning: Affected unit takes 1 damage every turn.
Corrosion: Affected unit has reduced defense.
Frozen: Affected machine cannot take any action and takes double damage.
Deploy Mechanics:
Deploy: This unit can skip a turn to switch between deployed and undeployed modes. While deployed, this unit cannot move. (Units with deploy cannot attack while undeployed)
Armored: Adds its movement value to defense while deployed.
Sniper X: Deals +X damage while deployed.
That's the selection I can make on first sight.