Previously, with Amethyst Spellstone, you had to actually take HP damage from your cards to activate the Spellstone effect. Diseased Vulture has the same text as Spellstone, but will activate even if you take damage with armor up. I had a game in Arena where the Warlock was at 6 HP and 6 armor, tapped with a Vulture on the board, and summoned a Flesheating Ghoul that snowballed and cost me the game.
Sorry to say, but you are wrong. Amethyst Spellstone triggers just fine if you loose armor, I just tested it:
And to add to the previous reply, Amethyst Spellstone and Diseased Vulture do not have the same text. There is a significant one word difference and you even mention that word, .
- Amethyst Spellstone - Lifesteal. Deal 3 damage to a minion. (Take damage from your to upgrade.)
- Diseased Vulture - After your hero takes damage on your turn, summon a random 3-Cost minion.
Diseased Vulture has no restriction on where the damage comes from. So, with Diseased Vulture, damage can be taken from the Hero Power, or using a weapon to attack a minion that has non-zero attack value.