Just some ideas that popped into my mind, i hope they aren't terrible .

Name: Bunker Buster Bomb.
Category: Special.
Rarity: Ultra rare.
Duration: N/A.
Cost: 95g.
Description: Inflicts 250 damage to a building. Requires allied aircraft unit in adyacent hex.

Name: Mustard Gas Bombardment.
Category: Special.
Rarity: Rare.
Duration 3 turns.
Cost: 40 g.
Description: Place two gas clouds that inflict 25 dmg per turn to any infantry unit that enters the hex. Target hex must be within firing range of allied artillery unit.

Name: Propaganda Leaflet.
Category: Special.
Rarity: Uncommon.
Duration: 2 turns.
Cost: 80g.
Description: convert enemy infantry to your side. Requires allied aircraft unit in adyacent hex.

Name: Sun Tzu's Doctrine
Category: Super Buff.
Rarity: Ultra Rare.
Duration: 3 turns.
Cost: 165g.
Description: gives three units +1 range, +1 movement, +1 vision, +25% damage and +15% armor.

Name: Tactical Retreat.
Category: Movement.
Rarity: Uncommon.
Duration: 3 turns.
Cost: 50g.
Description: gives three units +2 movement and -33% damage.