I love this card! That said, my love is likely through rose-colored glasses. Let's examine the con's first.

1. It's expensive.
2. It can be discard through Encounter card effects (every Encounter deck has Caught Off Guard)
3. Requires a Hero to make a basic attack (competes with other basic actions)
4. Must target Unique enemies (the Villain(s) and Unique Minions only)
5. Is Restricted (may compete with other Restricted cards) This is a pretty substantial list of cons. Godslayer is not an auto-include in any Hero's deck against any Villain; some consideration must be made.

How about the pros?

1. Is permanent (no Uses, no discard trigger)
2. May be used more than once per phase.
3. The Villain is always available to attack.
4. Unique Minions tend to have high hit points.
5. Can utilize Mean Swing without losing ability. The best case scenario for the Godslayer is when it is played early and then used often. As a permanent Upgrade, it has no upper limit to the additional damage it can cause. Combined with other Upgrades and effects, this card can provide a substantial source of damage against the Villain. If played early to mid-game, I've seen it provide at least 12 and up to 20 damage. Pretty good value for a 3 cost Upgrade!

Given these considerations, including the Godslayer in your deck should require that a Hero has certain characteristics. At a minimum, it would require:

1. The Hero plans to use their basic attack to deal damage (likely has a high base ATK).
2. The Hero has ways to Ready (through abilities, Upgrades, or Events)

So, who might want to include this card, and meets these basic criteria? Let's take a look, in release order.

1. She Hulk - One Two Punch, access to Limitless Stamina & Unshakable
2. Captain America - I Can Do This All Day
3. Thor - Access to Limitless Stamina & Unshakable
4. Spider-Woman - Self-Propelled Glide, deck build allows for additional readying cards and Upgrades from other Aspects.
5. Quicksilver - Super-Speed, Always Be Running. Just....insane.
6. Spider-Ham - Organic Webbing
7. SP//dr - Host Spider Some interesting use-cases might include Wasp (can split increased attack between targets, but no inherent Ready)and Valkyrie (Death-Glow can be awkward, competes with her Signature equipment) Interestingly enough, I don't usually run this with Gamora (pictured on the card). She is usually spreading her basic actions around , and wants cards that enable her to utilize her Finesse and Precision abilities. Godslayer knocks her temp down, taking her entire hand to play it.

So there you have it! some pros and cos to weigh, and some Heroes that might look amazing holding this powerful artifact.

Cards that combo well with this include:

-Dust: her ATK can affect every minion in play

-Thor: his ATK can affect every minion engaged with a player

-Tigra: additional ATK can help her defeat a minion to get her heal

-Beta Ray Bill: additional ATK can help him defeat a minion to get his thwart

-Magneto (campaign ally): additional ATK can help him defeat a minion to get his heal

-Lady Spider: her THW can affect two schemes

I love the concept but I think this card is overcosted by 1...
3 Effective Resources (ER) for 5 damage under condition is not good. And obviously, 2 damage is terrible.

I think 1 ER roghly equal to 2 damage so 2 ER would still be bad for 2 damage but would reward you for taking care of the main scheme by giving you a bit more value than usual but with a condition.

Time changes all things; and in the case of Hard Knocks it is Wolverine who has brought the winds of change to this card. While indeed cards like Tackle are more powerful overall; that has a pre-requisite required to unlock the damage in addition to the stun. If Wolverine plays that card using Wolverine's Claws he will only deal the stun; and while a stun for three hit points and a card is not the worst deal in the world, it's also not really good enough to include in most decks. So, instead let us look at Hard Knocks through the lens of the Captain Canada.

When used in a Protection aspect deck; Hard Knocks provides a way to utilise Wolverine's Claws defensively; as their activation is a Hero Action for an Attack Event you cannot funnel many of Protection's best defensive cards through it. Hard Knocks offers a way by allowing you to spend one card from hand (the Hard Knocks), exhaust the claws, lose three hit points and gain a Tough status card by defeating a minion with 4 or less health even if that minion has tough (because Wolverine's Claws gives this attack piercing). That's a huge deal for any Protection Wolverine in solo and it is also very relevant in multiplayer as you can both deal with a threat attacking one of your team mates plus take an attack without losing more any more hit points outside of the three already spent. Wolverine might have inbuilt healing, but Tough gives that Healing Factor regeneration a bit of time to recover from low health.

When we are not just leaning into Jimmy's decks Hard Knocks has a lower ceiling, but the floor for this card is huge in any hero who has great on board resource generation, ways of boosting its damage like Gambit or loves to have toughness like Colossus. Protection Thor is another place where this card has a great home because of Thor's preference for fighting minions with "Have at thee!". In the opposite style Drax likes this card also because he can use the tough status to gain vengeance counters without losing hit points. Last of all heroes with triple resource cards like Captain Marvel and Hulk are able to play this card for a net two cards instead of three or four.

Some other card to card synergies in Protection include Bait and Switch which will let you turn that toughness card into four damage right the villain's keister; Unflappable which will be triggered when you take no damage (thanks to tough) and classic Protection upgrades like Electrostatic Armor

All of this makes Hard Knocks a staple that you should pull out when you are starting to build a Protection deck and you should always seriously consider keeping it in the final build, cutting it only when it is clear that the deck is not needing an injection in the minion punching direction.

The Best Defense… is a good offense indeed.

At baseline, this is 4 thwart + 6 damage for 4 ER which is great. However the kicker is he needs to get charged up by you getting attacked so you need to mitigate 3 attacks without Stuns. Since Justice isn't the best at doing that, it means your character kit or Allies have to do the majority of the heavy lifting. This puts him at his best when playing Colossus as he's built to take hits to the face.