My friends on i started on it already just have to wait till version 6 to finish here is what we did:

Prequest: Goddess Skill (you should know what that is already lol) and Pandora/Medusa (quest in snow isle) needs to be done. Cause you need to meet King Herwerts servants Medusa and Dracula.

After those are done go to Athens there find the palace and you should see Medusa and Dracula standing in front of the Priestess and a few wounded soldiers. Go to her aid and a fight starts (had already done this in version 4) after you kill or wound Medusa and Dracula the Priestess will tell you to find Helios and gives you the Sun Badge to help you search.

Take the Badge with you and go to Rome. Enter the Colosseum and go to the back to where you see the pogleons or what ever those lil armadillo things are called. Once in the field go to the west portal you need the sun badge to enter the area. You'll see a (?) walk up to it and a scene will start some guards harassing a poor unicorn.. then a fight. After the fight Venus will appear and wish you luck with fighting King Herwert and will give you a flower to thank you and disappear taking the uni with her.

Return to Athens and find and talk to the old woman walking back and forth near the Cursed Palace entrance, around x:882 y:695. Again you need the sun badge and she will tell you about a small island south of Athens. you will need a boat or any vehicle. Go outside to world map and straight south about x:3312 y:2675 a message will pop up asking if you wish to enter the area, need badge and lily. Click yea and you will appear on a small island with a cave.

Enter the cave again you need the badge. On the second map head for the middle portal and you'll see a minotaur he called you his sacrifice and wants to eat you, you fight him. When the battle ends he's wounded and Athena appears to stop you just as you're about to deal the finishing blow. She tells you the minotaur was always good but is corrupted. She will aid and train it into fighting King Herwert with us, and then will disappear with it after you and her have a lil talk.

This is as far as my friends and i have gotten. So good luck. Only hard fight is the minotaur cause they can buff, debuff and has gs, but if you're used to NT event should be pretty easy just long with so much spawns.

Aniways later in version 6 you can continue by:

Going to another small island left of Rome need a vihecle and badge again. A cut scene should appear again enter the cave you find. and inside should be a trap door. Play a lil mini puzzle game to unlock it and enter.
Fight the guards blocking the entrance make your way thru till you find a box with a key inside. shoudl be a door next to it. Use it and enter to find Apollo. Dracula and Medusa pops up again and brings some new friends with them fight them and their guards.
After Venus and Athena will pop up, and after a cut scene the fight will start again.
After you have won again. Talk to Apollo. He will allow you to choose either Athena or Venus to go with you to help train in your fight against Herwert the other will accompany him.

^^ can't wait till version six cause i want Joan too.

Here is the guide i looked at when questing there is also a guild to getting Joan too: Venus, Athena and Joan