First of all, the official source and quotes from the same

Forge

[Old] 2/1 - On Reveal: Give the next card you play +2 Power.

[Change] …next card you play +2 Power. ->…next card you play +3 Power.

Many cards make great use of Forge’s effect, but he’s not quite powerful enough to be competitive at the moment. Given how many potential combos he has, we’re hopeful that a buff to Forge will have a really positive effect on meta diversity by enabling many new deck variations to be viable. Even though we’ve only increased his effect by 1 Power, cards like Deadpool, Multiple Man, and Brood can quickly multiply this increase to much greater effect.

Shanna

[Old] 4/4 - On Reveal: Add a random 1-Cost card to each location.

[Change] 4/4 -> 3/2

When we originally designed Shanna, we made her a 4-Cost to synergize with her companions Ka-Zar and Zabu. Even after a Power buff a few months ago, she hasn’t really found success so we’re going to try a different approach and push her down to 3-Cost. A Cost reduction should afford her more deckbuilding flexibility, and make her a more viable turn 6 play to add Power to each location.

Crystal

[Old] 4/4 - On Reveal: Each player draws a card.

[Change] 4/4 -> 3/3

Crystal has consistently been one of our weakest cards since day 1. We’re very cautious about pushing Crystal’s Power as SNAP’s small deck sizes make each card draw matter a lot more. However, we want to give every card a chance to at least see some play, so we’re giving Crystal a push with a Cost reduction to 3. This should allow her to at least be a consideration in Surfer, and maybe even help a Ronan deck out.

And for my personal thoughts: Huh. This was a short and sweet one. Targetting some very unpopular cards, and hopefully giving them a little boost.

I believe Forge now has some reasonable competition with Hulkbuster, though still obviously not as good as Phoenix Force.

Crystal has always been an interesting card for me since her rework, but also has too little synergy to be viable so a Silver Surfer candidate might get her to get noticed more.

And as for Shanna, well. IMO The power drop is somewhat dire, to me that made up for the randomness of her ability. Playing her earlier doesn’t make that much of a sense for me since they explicitly point out her synergy with Zabu. Moreover, the Zoo deck is simply too vulnerable to Destroy cards. Let’s see how this all shakes up, even if on my end I don’t think I’ll change any composition.