Fun game game, wildly unbalanced.
In general, blitz builds are pretty OP, but that is likely due to the random nature of opponent builds. Mana Potion + Fly Agaric + Spellbook + Damage x 3 usually kills on first turn. On the opposite side of things, spamming 5+ Chamomiles means you can just outlast until the turn decay gets into the double digits.
As for AI and enemies, them being randomly generated means I see stuff like a build of all single-uses and a Chamomile, which just dies.
As for items themselves: Scroll is objectively inferior to Sword. Tome is also objectively inferior to Sword. Non-Mana single use items often disappoint due to taking up space of a multi-use item, and Mana-only multi-use items become useless after all items enter play. Shield is also objectively superior to health, in that it stacks indefinitely, while health must be added with a combination of Max Health and Heal.
Again tho, fun little game, I'd like to see how it turns out after some updates.