I would never make or use a home-brew card in the game, and I would be slow to make suggestions to the designers, or share some wilder "thought-designs" of my own with the community any more. But the other night I was thinking of Éowyn and her card. Of course she can, and probably will, get a new version with different stats, but this one idea, though mine, seems quite neat.
Dernhelm
Tactics Attachment, cost 1, unique
Attach to Éowyn.
Éowyn gains the Tactics icon.
Planning Action: Exhaust Dernhelm to give Éowyn -3 willpower and +3 attack until the end of the round.