Does Convergent Mutation target both units (the one gaining might and the one providing the might value), and does the spell resolve without effect if the template unit is killed in response?

Ruling: Both units are targeted when Convergent Mutation is played, even though only one uses the word "choose" in the card text. If the unit providing the might value (template unit) is killed in response, the spell mistargets because that unit can no longer be found on the board, cannot find a might value, and resolves without effect.

Sequence:

• Play Convergent Mutation and choose both units (the one to gain might and the one providing the might value)
• If the template unit is removed before resolution, the spell mistargets
• The spell resolves without effect because it cannot find the might value

Nuances:

• The word "choose" in card text is not the determining factor for whether something is targeted - you target anything you have to choose