This is a question regarding the Hummerhorns Shadow effect.
If the Shadow effect of this card eliminates the defender from its associated enemy – is that enemy’s attack now considered undefended, and does the Shadow effect now deal 2 damage instead of 1? I wouldn’t think so, because at the moment when the Shadow effect is revealed, the attack is being defended.
However, the card text states “Deal 1 damage to each character…” (which kills the defender) followed by (2 damage instead if this attack is undefended) – which is now the case.
If the card text were to read “…if this attack was undefended” then I would be clear on the matter and deal only the 1 damage.