Inspired by Zahru's and Sigfig's ideas, I also made some faction based abilities, which are mostly limited to skill modifiers. I'm also open to any suggestions for these.
Poles
Hussar Wings
The Poles always take pride in having the most pompous wargear on the battlefield. The Hussar Wings are just a prime example for that, being awarded to the best warriors of the Polish Military.
A minifig, that is wearing Hussar Wings or piloting a vehicle with Hussar Wings is granted +1 Skill for each inch of wings. This bonus does not stack up with multiple wings. A unit may not wear Hussar Wings bigger, than the unit itself.
Soviets
Five Year Plan
After five whole years, the Soviet programmers finally managed to release the brand new update to the dated navigation chip, implanted into most cyborg's brains.
At Turn 5, each Soviet Cyborg units receives +1 Skill for the rest of the game.
Srbs
Giant
The most recognizable trait of the Srbs is their unusual height and strength, compared to ordinary minifigs.
Srb Giants have 2 HP and 3 Power Usage by default.
Generic
Born on the Settle
(preferably for Poles and Magyars)
While riding a horse, this unit is granted +1 Skill for any combat related action.