Any advise on how to be LAWFUL evil, and at that work this plan out at only level 5?

[Nightfall]

Firstly, since this IS Fierna we're talking about, don't really NEED to bother being a man. She might enjoy a woman for a change.

Just saying. It would be a riot all around.

Secondly, DO become LE. It's easier to corrupt the innocence than you would think.

Thirdly, join the follower of Helm, ONLY be the LE version, venerating (in private) your love and corrupting a lot to your side

Fourthly, to TRULY impress the Lord of the Fourth Layer, Kill off one of his rivals. No not some measely Duke, Duchess or something like that, Kill off either Mammon, Levistus or the Hag Countess, you'll be in good with Daddy dearest. Of course you could just worm your way into his heart, AND sleep with his daughter while being a woman. Hey no one said you had to play ALL the favorites.

Fifthly to TRULY impress Fierna, bring her some corrupted paladins that you've seduced to your side as loyal bodyguards. She'll be extremely pleased with that.

Finally NEVER take on an avatar. I don't care if you're 15 or 20th level, you'll be sorry you did.

Just one question, Miekkilli and Pelor?! Last I checked there was Lathander not Pelor.

 

[Rystil Arden]

And the good PC kept his alignment after doing that?

She managed to redeem an evil soul--how is that evil?

 

[Rystil Arden]

Finally NEVER take on an avatar. I don't care if you're 15 or 20th level, you'll be sorry you did.

I disagree--its OK to do it, but only if you have the Sceptre of the Sorcerer Kings artifact first, and reasonable faith in your ability with the dice to cut off the correct god/goddess from the material plane