If I hide Hidden Blade with my 5 might unit, can I unhide it on my opponent's turn when they play a 6 might unit to kill their unit without my 5 might unit taking damage?

Ruling: Yes, you can unhide Hidden Blade when your opponent brings in a 6 might unit. The Hidden Blade will kill the 6 might unit, your 5 might unit takes no damage, the opponent's unit dies, and they draw 2 cards.

Sequence:

• Opponent plays 6 might unit at the battlefield
• You unhide Hidden Blade
• Hidden Blade kills the 6 might unit
• Your 5 might unit takes no damage
• Opponent draws 2 cards from their unit dying