Regarding Ghostly Visage, bear in mind that you should get no damage reduction from that spell in the Red Lights, since it's 5/+1, and the goblin's weapons overcome the damage reduction.As for the zombie form, I can't say for certain. If you had a screenshot or server chat logs for the combat, it might help. As far as I know, it should absorb the first ten points of damage, provided they weren't using elemental/magical damage of some type. Again, though, without specifics, couldn't say.
However they do use oak bows, so arrows go through ghostly visage.