After a death, a resurrection, and a magical bond formed by breaking another magical bond, we come to the Tara of Season 8. Still building upon her magical powers, as well as her caring ways, the newfound connection between Tara and Willow allows for shared powers, whether voluntary or not. In terms of gameplay, this means you can drain one of them to allow the other to play a card. While the practical applications might be a bit limited due to the similarity between their talents and skills, flexibility is never a bad thing--and neither is Tara, for that matter.