This is the card that makes Thor's deck powerful, and there are only 3 copies. I think realistically, unless you're playing MP you can maybe luckily send off 2 copies for 16 damage. Either way, turn 1 with Mjolnir you can do 11 damage turn 1. Or 14 if you're packing a Mean Swing. This is the card I mulligan for, not Lightning Strike, or any other card, I want to throw the hammer again and again. Sure other targets like God of Thunder will definitely help, but Hammer Throw will get you to the finish line. Having GoT in play is also key to returning your hammer without having/needing a card in hand, so keep that in mind.
Hero Action (attack): Exhaust Mjolnir → deal 8 damage to an enemy and return Mjolnir to your hand. This attack gains overkill.
Throwing the Mjolnir is how Thor will kick butts in solo games. Lightning Strike is pretty situational to be honest in solo, as there won't be so many enemies deployed at once. Luckily, the hammer is very easy to get to your hand when in alter ego form.
Compared to Swinging Web Kick, we gain overkill which gives 100% of those 8 damage most of the time. Flavor wise, it is also very satifying to throw the hammer and having it going back to our hand. And can be used for an extra resource if needed to top off a very explosive turn.