Gust V Buff

If my opponent plays gust on my Wielder of Water with a 2 might, who’s defending alone so +2 might, with a buff +1, bringing it to 5, does that still send my unit back to my hand since its initial might is 2? Or does it not because my might is increased?

Gust: (reaction) Return a unit at a battlefield with 3 might or less to its owners hand.