Awesome - thanks for that! I'll just wait a few more levels

Hi all,

I have a question about the Nightblack Portal. When I try to "go portal", it seems I can't enter it (see cap below - I get a "The dark power of the portal forces you back!" message).
I'm a level 36 Paladin, who's neutral. Are there any restrictions on being able to enter it? I can't find ...