Can you cast Dragon's Rage if the opponent only controls 1 unit, just to move your own unit?

Ruling: It is currently unclear in the rules whether you must target the second unit when you play the spell or only when resolving it. If targeting is required on play, then you cannot play Dragon's Rage without a legal second target.

Nuances:

• The use of "then" in the card text suggests the effects are successive rather than simultaneous, but this interpretation is not yet confirmed
• Targeting rules are expected to be updated in the future to clarify this interaction
• There is a dedicated thread discussing Dragon's Rage specifically