Can I play Shen when enemy units move to my controlled battlefield?

Ruling: Yes, you can play Shen when enemy units move to your controlled battlefield. When a battlefield you control becomes contested by an enemy moving into it, you retain control of that battlefield until the contested status is lifted (likely at the end of combat).

Sequence:

• You control a battlefield
• Enemy moves units into your battlefield
• The battlefield becomes contested
• You retain control during the contested state
• Shen's requirement of controlling the battlefield is met
• You can play Shen as a defender

Nuances:

• You cannot play Shen if the battlefield was NOT controlled prior to the move (i.e., if it was already uncontrolled before the enemy moved in)
• When played in this situation, Shen is considered a defender and receives his shield bonus