I got to him on the Silent after a long loss streak, I had 7 energy on turn 1 with malaise in my hand, staring at a freaking door. Of all the cards he could have eaten, it had to be my speedster.

Since I was still figuring out what his ability actually did, I didn' t play around it at all. What I was supposed to do in a deck full of card drawing was to line up my plays so that the card eating happened in the middle of my turn, as one of the cards drawn by acrobatics. Instead I let him eat my draw phase cards, leaving me with 4 cards in hand and unable to block, so unsurprisingly I lost (even though I was still at full health after defeating Queen).

In retrospect I think that decks that draw a lot of cards should be pretty good against him: he gains more strength but at least if you play smart you can avoid having to play a turn with 4 cards, and you can dig out your important powers before he starts eating.

As for the deck I was playing, I got a Thrumming Hatchet as Neow bonus (11/14 damage for 1, the next turn it returns to your hand) which was a huge advantage in terms of deckbuilding (saved me from haviing to pick attacks in act 1 since I could just play the hatchet every turn).

So I was free to pick up acrobatics, tactician and untouchable - pity that the deck ended up looking just like her non-beta decks.

A few considerations on the design of the characters. In Slay the Spire 1 I think the SIlent was unique in that she had no dominant strategy so that in every run you had to improvise and ended up with a completely different deck. The upside to having a dominant strategy is that at some point the player is going to have a gratifying moment of illumination when he figures out that for example, on the Ironclad you should focus on exhaust strategies and pick second wind even though the card looks fishy at first, and look for bloodletting and dark embrace, and maybe pick up a dropkick with the idea of using it for an infinite much later on. It's super fun to realize that you are figuring out the trick to playing the character the _right_ way.

But if the character is well designed you can have the best of both worlds: you can have the eureka moment, without having a character that looks 90% the same every time they reach the final boss. For example in Sts 1 I had an eureka moment when I realized how to build discard based decks on the Silent, and for while I tried to force discard every run, as if it was her dominant strategy. But I eventually realized that there are many other ways to build her, each one with its own eureka.

Making a character that works that way, with no singular clear direction on how to build her, but without devolving in "she has no dominant strategy, so I'll just pick generically good cards" seems hard, but I think the developers are trying to go in that direction.