I crafted 2 of these weapons and they only seem to cast when you use their item cards. For example, the death shadow-forged weapon would only cast Skeletal Pirate when I use the Deathtrap item card; and in the update notes, it says these weapons can cast during opponents turns, the caster's turn, or even our ally's turns. Is this a bug or have they just not casted yet?
yea I noticed the same, I have 3 shadow weapon's myself, Root of Spring, Fragment of a Dream and Shadow's Point. I believe KI hasnt implemented the ability to may cast for weapons yet. The only have 50% chance of casting after the item card like you said. Its not a bug, just a delay in implementing the actual ''may cast'' ability for the weapons