been playing this, absolutely love it. Would say, the knife deck you can fairly consistently build is a bit too strong. the summon who heals each time you use a knife coupled with bladed wand makes thorns insignificant. Also blows through the seagull boss because the discard mechanic is ignored by knives. Really have enjoyed everything about the game otherwise though. Knives are just a bit too strong imo.
you could add a limit to how much healing the summon does, or reduce the bladed wand damage. It'd be a bit wordy, but in my opinion the biggest problem isn't the damage of the knives but the consistency/durability they have. If you reduce the draw from bladed and add a limit to the summon, it'd be fine. Maybe it could read something like "Whenever you play a knife, restore one health and this minion loses one health" So if you keep it up on the board it still has a limiter.
FYI the limit to the knife summon seems not to be functioning. If I understand the card-text right, he should be losing health as he heals, and heal only up to 3 health (or whatever his health is at the time knives are activated). For me, all copies of the knife summon are healing an unlimited amount, and not suffering any health loss from healing.