[quote=@Raineh Daze]
<Snipped quote by IncredibleBee>

What I'm saying is that you're not going to automatically succeed at cutting through a magical item. If the 'magical' part is something like 'nigh invincible', then it doesn't matter if you can cut something that isn't even physical.
[/quote]

Actually it does matter because the Dragonslayer cuts physical and magical materials simultaneously, by virtue of being a physical weapon imbued with astral properties.