Can you target a 4 might friendly unit with Gust, even though it won't have any effect?

Ruling: No, you cannot target a unit with 4 might with Gust. The 3 might restriction is a targeting restriction, and the target must be valid at the time of playing Gust.

Nuances:

• This means you cannot use Gust on your own 4+ might unit (like Irelia) as a way to trigger other effects while having no effect on the unit itself.