+2 cards and -3 threat in exchange for a minion which will likely die from a hammer throw? Easily Thor's best card. I will always play this unless there's no threat on the scheme for some reason. However there are some villains like Rhino who has less minions in their deck so watch out for that.
Hero Action (thwart): Discard cards from the top of the encounter deck until you discard a minion. Put that minion into play engaged with you → remove 3 threats from a scheme.
Thor #3. Thor #2-3.